Carl is the only son of deputy sheriff Rick Grimes and his wife, Lori Grimes. When the dead rise, Lori takes Carl to a purported safe zone in Atlanta, Georgia, along with Rick's partner, Shane Walsh. Lori and Carl join a group of survivors on the outskirts of Atlanta, formed and led by Shane. There, they are eventually reunited with Rick. Despite being only seven years old, Carl is taught to shoot a pistol. This comes in handy when he saves his mother from an attacking walker. Later, he is forced to kill an unstable Shane in order to protect his father.
After the group buries Shane and leaves Atlanta, Carl is shot and wounded by ranch foreman Otis while searching for supplies in the woods. The survivors are brought to the farm of Otis' employer, veterinarian Hershel Greene, who successfully treats Carl. The group remains at the farm for several days until tensions cause Hershel to evict them.
They eventually find an abandoned prison. While there, Carl and the others enjoy the prison's luxuries, such as hot showers and open space. He is confronted with disturbing experiences, such as witnessing numerous counts of violence/death. While Rick was away with other survivors, he frequently gave Lori re-assurance about his well-being. Throughout Lori's pregnancy, Carl was thrilled with the idea of a baby sister and when Judith is born he is fiercely protective over her. When The Governor and his army attack the prison, Carl managed to escape with Rick.
During the journey, while returning to Kentucky with Rick and Abraham, he is nearly raped by a group of rednecks before his father manages to kill all of them. In the aftermath of their murders, Carl confesses to killing Shane and being a different person than he was before the apocalypse. Shortly after their return to the main group, Carl witnesses a fellow child survivor murder his brother, and he secretly kills the child when he realizes no one else is willing to do it. He feels deep grief, but does not regret his actions.
When they arrive at a gated community in D.C., Carl is unable to fit in with the other children due because of his horrific experiences in the dangerous outside world and the false sense of security the other children had. During a zombie attack, Carl is shot in the face, losing his right eye, and in a coma for weeks. When he wakes up and again is taken care of by Rick, he shows a much more negative outlook, berating his father for all of the horrible things that have happened because of him.
When Rick decides to attack a group of survivors known as the Saviors, they retaliate by killing Glenn. Rick decides to create the illusion of falling in line with their leader, Negan, but is actually trying to find more information about the group when Carl decides to sneak into one of the Saviors' vans and launch an assault on them, ending with him as Negan's new "guest". Negan grows a liking for Carl, although Carl remains resentful towards him. Not long after, Carl is returned to Rick unharmed. He accompanies Rick to "The Kingdom", a neighboring settlement led by Ezekiel. There, they plan to go to war with The Saviors. Carl stays back in the Safe Zone while Rick ventures out to Negan's stronghold for war.
After the two year time gap, Carl decides he wants to leave the Safe Zone to journey to The Hilltop and start an apprenticeship with Earl Sutton, the blacksmith. Shortly after arriving there, two boys attack him and Sophia who Carl beats off with a shovel, nearly killing them. He is temporarily held in a cell where he bonds with Lydia, a survivor from a rival group, The Whisperers. After being let out Carl convinces Maggie to let Lydia out under his watch and they bond further eventually Lydia seduces him and they make love. Though Carl and Lydia grow even closer after this Lydia's mother "Alpha" arrives at the Hilltop's gates demanding Lydia back or she will attack and Maggie is forced to hand her over, a decision that highly enrages Carl. Later when Sophia goes to check on Carl he is missing and is revealed to have sneaked out after Lydia.
Carl is Lori and Rick Grimes' son and Judith's elder half-brother. Carl loved both his parents, even though they began to have marital issues. Upon learning of his father's shooting days before the outbreak, he is devastated, even wanting to give a blood transfusion to help which his mother talks him out of. When the outbreak begins, Shane Walsh and Lori take him to the supposed safe zone in Atlanta. On the way there, he is told that his father is dead, and he gradually began to accept it but had little time to mourn. On the way to Atlanta when traffic is backed up Carl, Lori and Shane meet Carol, Ed and their daughter Sophia who Carl quickly becomes friends with. They set up camp with other survivors on the outskirts of Atlanta, Carl begins to look at Shane as a father figure, as he does various activities with him such as fishing and learns some survival skills from him, but appeared to be oblivious to Shane and Lori's ongoing sexual relationship.
In the series premiere "Days Gone Bye", Carl is seen with Lori and Shane at the survivor camp outside of Atlanta, and has made friends with a girl named Sophia. In the episode "Guts", Carl is in the camp when T-Dog makes contact as part of the group that went on a supply run to Atlanta. In the episode "Tell It to the Frogs", when Rick returns with the group from Atlanta, Carl is overjoyed and Lori restricts Carl's interactions with Shane. In the episode "Vatos", walkers overrun the campsite, killing and injuring many quarry survivors. In the episode "Wildfire", Carl and the group travel to the CDC. In the season finale "TS-19", Carl and the group enjoy the facility's amenities. Following the CDC's destruction, they start traveling again.
In season 2, Carl is shown to be yearning for more responsibility within the group, such as helping to scavenge for supplies. In the season premiere "What Lies Ahead", while searching for the missing Sophia, Carl is shot and wounded. In the episode "Bloodletting", Otis, the man who accidentally shot Carl, leads Rick and Shane to a nearby farm. The owner, Hershel Greene, treats Carl but reveals he will need surgery to save his life. In the episode "Save the Last One", Carl wakes up briefly and talks to Lori about the deer he saw right before he was shot. Shane returns with the necessary medical equipment for the surgery, but lies about the fact that he shot Otis to save his own life. Hershel operates and saves his life. In the episode "Cherokee Rose", Carl wakes up as he recovers, and Rick gives Carl his hat and badge. In the episode "Chupacabra", Carl appears in a flashback from before he and the group arrived at the camp outside of Atlanta. In the episode "Secrets", Carl is recovered and helps his mom feed chickens on the farm; he begins to develop a colder mindset, which worries Lori. In the mid-season finale "Pretty Much Dead Already", it is revealed that Sophia was a walker and being kept in Hershel's barn; Carl watches as Rick shoots Sophia in the head.
In the mid-season premiere "Nebraska", Carl's new colder mindset continues to develop following the reveal of Sophia as a walker. In the episode "Triggerfinger", Carl learns that Lori is pregnant. In the episode "Judge, Jury, Executioner", Carl denies the idea of heaven and shows disrespect towards Sophia's mother Carol for mentioning that Sophia was in heaven. Carl finds a walker stuck in mud in the woods and taunts it, but the walker frees itself and starts chasing him; this walker later finds Dale and mortally wounds him. In the season's penultimate episode "Better Angels", Carl saves his father by shooting Shane, who had become a walker. In the season finale "Beside the Dying Fire", Carl's gunshot attracts a horde of walkers and so the group is ultimately driven off the farm.
In the season premiere "Seed", six to seven months later, Carl has evolved into a child soldier of sorts; he has grown more proficient with weapons, and has adapted a more mature demeanor, as well as a more responsible role within the group. Carl is with the group as they setting into an abandoned prison. He has grown distant from Lori and shows a developing crush on Hershel's seventeen-year-old daughter, Beth. In the episode "Sick", Carl sneaks off alone to find the prison infirmary, brings back much-needed medical supplies, but Lori scolds him for going off alone. In the episode "Killer Within", after watching his mother die while giving birth via C-section, a distraught Carl shoots her per her request to prevent reanimation. In the episode "Say the Word", Carl watches as Rick storms off to find Lori's body. In the episode "Hounded", Carl, Daryl, and Oscar find Carol, who had been missing and presumed dead from an earlier walker attack. In the episode "When the Dead Come Knocking", Rick lets Carl name his new sister, and he names her Judith after one of his school teachers. While Rick, Oscar, Daryl and Michonne head out to attack Woodbury, Carl is left in charge of protecting the others inside of the prison. In the mid-season finale "Made to Suffer", upon the arrival of Tyreese's group, Carl takes the initiative to lock them all out of his cell block.
In the mid-season premiere "The Suicide King", Carl keeps Tyreese, Sasha, Allen, and Ben locked up, and when Rick returns he yells at them to get out of the prison. In the episode "Home", Carl and Glenn investigate the breach where Tyreese's group got into the prison, and report back to the group that the boiler room is overrun with walkers. In the episode "I Ain't a Judas", Carl tells Rick to take a break from being the leader, as the stress has been too much for his father. In the episode "Clear", Rick, Carl, and Michonne make a run to Rick and Carl's home town, where they encounter Morgan Jones, and Carl bonds with Michonne. In the episode "Arrow on the Doorpost", Carl helps Glenn and the rest of the group organize their arsenal. In the episode "This Sorrowful Life", Carl helps Maggie create a diversion to distract walkers at the fence. In the season finale "Welcome to the Tombs", Carl kills a teenage member of The Governor's army, who failed to drop his gun, despite professing to surrender, when the boy stepped closer to Carl, Hershel (who was unarmed), and infant Judith. Carl tells Rick he did not want to take his chances by letting someone else live who could potentially kill someone in their group; he brings up how he did not kill the walker on the farm that killed Dale and how Rick's decision to not kill Andrew and The Governor resulted in the deaths of Lori and Merle, respectively. Carl also appears angered by Rick's decision to take in Woodbury's remaining survivors, who generally appear to be less able-bodied.
In the season premiere "30 Days Without an Accident", Carl has turned to farming along with his father, Rick tries to encourage Carl to be a kid, but Carl hardened by what he's seen and done is reluctant to do so. He does go to "Storytime" that is hosted by Carol which included teaching the kids how to use weapons when needed. In the episode "Infected", Carl tells his father about Carol training the children with knives. After an infection breaks out in the prison Rick lets him carry a gun again. In the episode "Isolation", Carl helps Hershel pick elderberries, which Hershel will use to make a tea for the sick. In the episode "Internment", Carl helps Rick reinforce the fences, but when walkers break through anyway, Rick and Carl arm themselves with assault rifles and gun them down. In the episode "Dead Weight", the Governor secretly watches Rick and Carl digging in the prison yard. In the mid season finale "Too Far Gone", Carl tells Daryl he has a clear shot on The Governor, but Daryl tells him to not take the shot as a firefight would break out. During the fight he saves his injured father before finding his sister's carrier empty and bloody. Devastated, Rick and Carl leave the prison as walkers invade with Rick telling Carl, "Don't look back."
In the mid-season premiere "After", Rick and Carl found a house in a neighborhood. Carl feels like he doesn't need Rick anymore and while Rick lays unconscious Carl starts scolding him about how he wanted to plant vegetables and hide while The Governor knew where they were. He goes on to state that he never forgot how to survive while it happened. He is later seen luring two walkers away from the house to kill them somewhere where noise won't attract other walkers. He successfully lures them away but encounters a third walker and nearly gets killed. He goes to a house and discovers another walker in one of the rooms. The walker nearly kills him but Carl gets away losing his shoe in the process. He eats pudding he found in the house while sitting on the roof. He later returns to the house and Rick rises from a couch being used to block the door from walkers. Thinking that Rick is dead, Carl raises his gun at Rick, only to cry saying that he is scared. The next day, as they are sitting near the couch, they hear a knock on the door. It is revealed to be Michonne after she found the pudding that Carl ate the day before. Rick looks at the door and says it's for Carl. In the episode "Claimed", while Rick stays back at the house to recover, Carl and Michonne set out on a supply run where they further their bond, and Carl learns that Michonne once mothered a son. They return from their supply run to find Rick fleeing the house due to it becoming occupied by a hostile group of men. Carl accompanies Rick and Michonne on foot until they come by a train car with a sign attached which points out a sanctuary known as Terminus. In the episode "Us", Rick, Michonne, and Carl travel along the train tracks towards Terminus, unaware that they are being tracked.
In the season finale "A", on the way to Terminus, they are confronted by the hostile group who now have Daryl in their employ. Daryl retaliates against the hostile group, and the confrontation quickly escalates. During the ensuing fight, a man attempts to rape Carl, but is stopped and killed by Rick. Carl, Rick, Daryl and Michonne continue to follow the tracks, eventually reaching Terminus. Rick decides to have his group sneak into the compound to avoid detection, remaining cautious of its current residents. They find the Terminus members in a broadcasting room, and are greeted by Gareth, the apparent leader. Gareth escorts Rick's group to the courtyard where other Terminus members are situated. Rick notices a Terminus resident in possession of Glenn's watch and quickly deduces that something is wrong. He draws his weapon and demands to know where Glenn and the other people from the prison are. Gareth has his men open fire on Rick's group and strategically rounds them up to a train car. Rick, Carl, Michonne and Daryl are forced to drop their weapons and step into the train car where they are held prisoner. Inside, they are reunited with prison group survivors – Glenn, Maggie, Bob and Sasha, along with new group members Tara, Abraham, Eugene and Rosita.
In the season premiere "No Sanctuary", Carl remains in the train car until his father releases him and he helps the group escape Terminus. Afterward they are reunited with Carol and Tyreese, who also saved Judith, whom Carl and his father are overjoyed to see alive. In the episode "Strangers", Carl insists they help a priest named Gabriel while Rick is willing to let him die but everyone in the group is suspicious of how normal he seems as he takes them to the church. Before leaving on a run Rick insists Gabriel can't be trusted, at least not yet, and tells him to not let his guard down. Carl also finds claw marks on the walls and the words "you'll burn for this". In the episode "Four Walls and a Roof", when Rick and a few others leave to ambush Gareth, Carl stays behind to protect Gabriel, Eugene, a dying Bob and Judith along with Rosita and Tyreese. After Gareth's death he remains at the church whilst Abraham takes half the group to start heading towards Washington DC. In the episode "Crossed", Rick takes another group to rescue Beth. Carl, Michonne, Judith and Gabriel remain in the fortified church to wait while Carl tries to convince Gabriel that if he's with their group he needs to defend himself and gives him a blade. In the mid-season finale "Coda", when Gabriel leaves the church then brings walkers back to it, Carl helps fight before taking Judith and escaping under the floors of the church. He and Michonne then lock the walkers inside the church. When Abraham returns they all head to Atlanta to regroup with Rick. He remains in the truck whilst the rest head into the hospital to find Beth, discovering her dead.
In the mid-season premiere "What Happened and What's Going On", Carl is present for Tyreese's funeral. In the episode "Them", the group continues their trip to Washington D.C. and Carl tries to cheer up Maggie, still grief-stricken by Beth's death, a music box and the group finds themselves in a barn during a storm as a herd of walkers tries to get in and Carl helps keep the door shut until the storm kills the walkers. In the episode "The Distance", Maggie and Sasha bring a stranger, Aaron, back to the barn who claims to be part of a community and wants them to join but Rick is distrusting of him whilst Carl, Michonne, Maggie and Sasha aren't. When Rick expresses uncertainty of taking up Aaron's offer Carl immediately protests against his father and wants to go and eventually they arrive at his community, the Alexandria Safe-Zone. In the episode "Remember", each group member is interviewed by Alexandria's leader Deanna Monroe and Carl tells her that he was the one to kill his mother but believes she would be happy to see that he and Rick have found the place Lori had wanted them to find. Carl is also introduced to Ron, Jessie's teenage son, who introduces him to Mikey and Enid, a young girl Carl seems to like, but also hearing them talk of video games and schools which stuns Carl who hasn't heard those words for years. Though Carl does like them he also believes they are weak from inexperience and becomes worried that being in Alexandria will make him weak also. Later Carl spots Enid climbing the wall with a bag of supplies and follows her to investigate but she mysteriously vanishes as he also finds his father engaging some walkers, but is almost killed because of self-doubt because of Carl's earlier concern and Carl saves him. Carl and Rick return in time to break up Glenn and Aiden, Deanna's son, fighting each other and Carl sees Enid return but she just ignores him and walks off. In the episode "Forget", Carl begins to adjust to Alexandria and is now friends with Ron and Mikey whom he is seen talking to at the house welcoming party in Deanna's home. In the episode "Try", Carl sneaks out after Enid again and she tells him to stop following her. He tries to convince her that it is dangerous outside the walls, but she believes they are meant to be outside and provokes a walker to chase them which Carl actually enjoys. Carl tries to learn why he creeps Enid out but she simply states that he just does. As they are sitting down Carl tries to learn more about her life before Alexandria, admitting that things happened to him, but she does not want to talk about it. They soon hear walkers nearby and take shelter in a hollowed-out tree. As the walkers are walking by Enid states that the world is theirs now and humans just live in it, and as they gaze into each other's eyes Carl holds Enid's hand but quickly pulls away and Enid teases him saying that he is scared of her too. However this does not classify them as love interests, seeing as the development of their relationship in season six puts them on an entirely different track. Carl and Enid return later to see Rick attacking Pete. Carl tries to stop him but Rick shoves him away and Carl watches as Rick begins scolding Deanna and the other Alexandrians for believing they are safe, until Michonne knocks him out. In the season finale "Conquer", Carl appears when Rick shows up at the house to check on Carl. Carl asks his dad what his plan is, but Rick instead tells Carl to stay at home. Carl asks if this was "home", to which Rick answers "yes". Later Carl appears at the house holding Judith listening to the music box he gave to Maggie to help her grieve over Beth's death
Midway through the season, Rick and the others settle in Alexandria, but some inner conflicts prove troublesome which results in a lot of deaths. Alexandria is also invaded by a large horde of walkers, and one of the young residents (Ron Anderson (Austin Abrams), the son of Pete Anderson, the man Rick had executed in the Season 5 finale) turns hostile after witnessing the deaths of his mother Jessie & brother Sam from the walker herd, firing a shot that claims one of Carl's eyes, but Ron is killed by Michonne.
Carl further develops his friendship with Enid (Katelyn Nacon), who often sneaks out of the safe zone when she is distressed. Eventually, the Saviors (led by Negan (Jeffrey Dean Morgan)) are revealed to be the newest and deadliest threat to the group to date, as they violently scavenge other communities for their supplies. but Rick and company manage to kill a lot of them in one of their compounds.
In the season finale "Last Day on Earth", Glenn, Rosita, Michonne and Daryl are missing because the Saviors captured them. Carl later goes with his father and several others to get a very ill Maggie to the Hilltop after she experiences complications from her pregnancy. En route to the Hilltop, they discover all the roads are intentionally blocked by these dangerous people. Eugene then takes their RV alone at night, to be bait while the others go through the woods on foot. However, Eugene ends up captured and soon, the others are surrounded and disarmed as well. Forced to their knees, Glenn and the others are brought out of a van, and also made to kneel down. Negan then steps out of their RV holding a baseball bat wrapped in barbwire. He proceeds to torment the group, issues his demands, and randomly beats to death one member of Rick's group, as a punishment for them killing off a lot of his followers. Negan threatens to cut out Carl's remaining eye and feed it to Rick should anybody try to stop him.
Carl returns in the season premiere "The Day Will Come When You Won't Be". After Negan kills Abraham with Lucille, Daryl tries to attack him as Rosita is being intimidated, which causes the others to watch as Negan murders Glenn as well, since he promised to "shut that shit down" if anybody else got out of line. Carl is later brought forward by Negan, and he instructs Rick to cut off one of his arms, with Carl even telling Rick to do it or everyone will be shot by the Saviors as Rick watches. However, it is actually revealed to be a test to break Rick's will, as Negan stops him short of doing so. Negan and his people then leave the survivors a truck, saying they will return in one week to get their offerings, but they keep Daryl.
Carl next appears in "Service" where he shows anger at his father and Michonne's willingness to obey the Saviors. When Negan and his men arrive for their offerings, Carl attempts to stop a Savior from taking all of their medicine at gunpoint as the Saviors stated they would only be taking half of their stuff. Negan tells Carl that he likes him, but that he won't tolerate someone threatening him or his men lest he be forced to kill someone else which makes Carl lower his gun. This action spurs Negan to take all of Alexandria's firearms as he no longer trusts them to have such a privilege.
In the episode "Go-Getters', Carl catches Enid sneaking over to the Hilltop and decides to accompany her there. He tells her of his plans to kill Negan though he admits that it will be more for him than anyone. When they arrive, they find the Saviors there and Carl decides to use them to find Negan. Enid attempts to convince him to stay, but he still leaves (though not before the two share a kiss). The episode ends with Carl riding towards the Sanctuary in one of the Savior's trucks where he is joined by Jesus.
The seventh episode of the season "Sing Me A Song" follows Carl and Jesus riding to the Sanctuary. Once they get close, Jesus suggests jumping out of the truck and following on foot. Carl agrees, but allows Jesus to jump out while he stays on the truck. Once inside the Sanctuary, Carl uses an assault rifle from the load to open fire on the Saviors, killing two of them before demanding they surrender as he only wants Negan. Negan steps forward and praises Carl's tenacity before he's disarmed by Dwight, though instead of harming Carl, Negan takes him on a tour of his community (including his harem of wives). Deciding he wants to get to know Carl better, Negan demands he remove the bandages around his eye. Carl begrudingly does so and is nearly brought to tears by Negan's comments about the deformity. Seeing that Carl is upset, Negan apologizes as he forgot he's just a kid. Carl is then forced to sing Negan a song while he swings Lucille dangerously close by. Carl is later a witness to Negan using a hot iron to burn the face of a Savior who reunited with his former wife (now Negan's wife) before Negan decides to bring him back to Alexandria. Throughout the episode, Carl still shows the same anger at Negan and at one point tells him to "jump out the window to save me the trouble of killing you" while also curious why Negan hasn't killed him or his father yet. The episode ends with Negan replying that he may do just that.
Carl's character development has been well received in both mediums.
In "Judge, Jury, Executioner", Carl evolves into a desensitized character and ultimately relinquishes his naïveté to the world around him. Although Entertainment Weekly writer Clark Collis drew parallels to a serial killer, Kirkman suggested this was an initiative to give more screen time to the character. He avouched that Carl was "one of the most fun characters to tell stories about in this world." He continued: "It's true of the comic and it's true of the show. Over time, we’re going to start to see more and more of this kid. What's awesome about that is, think about what it would be like to grow up in this world. It's one thing to have everything you know taken away from you and have to deal with this s—y world you now have to live in. But to have barely even really recognized what the world is and how it works and what to expect and then to be thrust into this apocalyptic threat and to grow up and mature with these kinds of situations. It's going to make him grow up weird, is what I like to say."