"A" makes appearances as a figure with black leather gloves, a black hood, dark pants, and dark shoes. Throughout the seasons, the story focuses on the mystery of "A". However, "Big A" also sported different disguises, including those of Red Coat and The Black Widow.
Uber A also dressed up as several disguises, including those of a gardener, a maid and a surgeon. They later costume themselves with the traditional look.
Three years after the disappearance of Alison DiLaurentis, her four friends, Aria Montgomery, Spencer Hastings, Emily Fields, and Hanna Marin, each receive messages from someone calling themselves "A." The girls had drifted apart over the years, so they had no idea that other people were getting texts as well. Additionally, the texts were about secrets only Ali knew about. At first, the messages were simply teasing and all of the girls wonder if their missing friend was the one who sent them. Though they knew she was most likely dead, she was still the only one who knew their darkest secrets. Once Ali's body is discovered in her old backyard, the girls are even more baffled when they continue to receive threats. At Ali's funeral, the girls are reunited and they find out that they've all been receiving weird messages. As the girls stand outside after the funeral ends, they all get a text saying, "I'm still here, bitches. And I know everything. —A".
From that point on, the messages take on a distinctly more threatening tone. Aria is given an ultimatum to tell her mother about her father's affair by midnight after the Foxy event, or A will do it for her. A continues to play life-altering games with the girls, from encouraging suspicion of Spencer's involvement in Ali's death to outing Emily's sexuality to her conservative mother. However, A makes a serious mistake in texting Hanna on the night of Mona's birthday party. Instead of using the plain Blackberry she bought just for tormenting the girls, A accidentally uses his/her own phone. Hanna, who has a new phone without all of her contacts recognizes the number, compelling A to act before Hanna can reveal A's true identity to the others. A hits Hanna with an SUV, successfully destroying Hanna's phone and putting her into a coma that eventually leads to a temporary loss of memory. Soon after that, "A" puts a drug in Emily's pain cream which causes an Ulcer in the spot where she has been putting the cream. She ends up in the hospital and might not be able to swim again.
A knew that there was a very good chance Hanna would regain her memory. Hanna's best friend, Mona Vanderwaal, informs the girls that she has also received texts from A, drawing the five closer together in trying to figure out who their tormentor is. Mona subtly encourages Spencer's fears that her sister, Melissa, might be A as well as Ali's killer. During Hanna's recovery masquerade celebration, she suddenly regains her memory, revealing that Mona is A. However, she, Emily, and Aria can't do much about it, because Spencer and Mona are on their way to the police station. After Spencer is warned about Mona by text, she tries to escape Mona's car, but Mona catches on rather quickly and diverts to a path in a more remote area of Rosewood. She tells Spencer everything, from seeing Ali launch a firework into Toby Cavanaugh's treehouse and blind her friend Jenna, to finding Ali's diary of secrets among a pile of old DiLaurentis junk the St. Germains left at the curb, discovering the girls' secrets that only Ali knew. Her motivation was to get revenge for her friend's blindness, even though Jenna and Ali had planned together to launch the firework. Mona didn't know this and got a scar on her stomach from the ordeal. Mona also drops the bombshell that Ian Thomas killed Ali, due to Ali's last diary entry about giving him an ultimatum to break up with Melissa. She then offers Spencer to become A with her and tell Hanna that she must not be remembering correctly, but she refuses. The two fight at Floating Man's Quarry and Spencer accidentally pushes Mona, who falls and has her neck caught between rocks.
As the girls move into the big red house they are shocked to receive messages from a new person claiming to be "A". At first, they believe it's just a prank, especially since the first "A" got major news time. Then the girls believe it's Ian Thomas, who is the prime suspect of the investigation. Spencer is especially certain of this until finding Ian's body in the woods bordering her estate and the old DiLaurentis home. The girls all get a message from "A," saying "He had to go. -A".
However, this "A" is even more twisted than the first; Ian's body disappears and the town is largely convinced that it was a hoax. "A" even teases Spencer, stating, "Just because I said Ian had to go, it didn't mean he had to die." "A" pretends to be Ian, using an IM screenname of USCMidfielderRoxx, a testament to his alma mater and his love for field hockey. Through this new fake identity, "A" feeds Spencer some interesting information about her family, specifically her father's affair with Mrs. DiLaurentis and the possibility that Ali is her half sister. "A" proceeds to torment the girls even more: they force Spencer to focus more on her father's secret by enabling Spencer's surrogate mother to scam her and clear out her two million dollar trust fund. "A" taunts Aria with pictures of her and her mother's new love interest in compromising situations. They threaten to send these to her mother, even though Aria has tried to ward off her mother's new boyfriend. "A" lands Hanna in the Preserve at Addison-Stevens, a lush clinic for troubled patients. "A" sends Emily on a trip to the Amish community in Lancaster to dig up more dirt on Officer Wilden.
Throughout the second half of the series, the second "A" keeps up this forced information search with the girls, pushing them to find more information on Wilden and Jason DiLaurentis. "A" even plants the idea that they killed Ali. However, when Jenna is found dead in Heartless, "A" plants all of their texts, pictures, etc. on a random lecherous construction worker. This is one of the same workers who was involved in building the DiLaurentises' gazebo when "Ali" was still alive. The girls believe it is all over now, though the fact that the suspect is such a random person bothers them.
Everyone in Rosewood is shocked when the DiLaurentises introduce the existence of a third child, Courtney DiLaurentis. She is the twin of Alison and was kept in various clinics because she was "ill". However, "Courtney" is actually Alison DiLaurentis herself. She reveals her true identity to each of the girls, hoping to gain their friendship and telling them she never died the night of the sleepover. She claims that Courtney must have gotten out of the house and ran into the construction worker, who killed her. Though the girls believe her and are glad to have their friend back, Aria is the most suspicious of her. It was recently discovered that Courtney liked to pretend to be Ali and she wasn't completely buying her story. Additionally, Wilden and Melissa are also suspicious of "Courtney". Melissa knew about the twins since high school, as their brother Jason confided in her. He told her they hated each other, but Spencer tells her about "Courtney's" statements that she and Ali shared everything together."
Ali's time is running out, for besides the few people suspicious of her, the police start to say that the construction worker has an alibi and might not be guilty. Her secret is further endangered when Aria finds and sends in a photo of a reflection of someone spying on the girls during the sleepover. The reflection is too blurry, but it is clearly a female. Ali takes Mona's idea and convinces Spencer that Melissa is the culprit. Meanwhile, she kidnaps Melissa- who has just figured out the truth- and keeps her in her family's Poconos home. She stuffs Melissa in a closet with Ian's corpse.
On the night of the school's Valentine dance, Ali convinces the girls to hang out with her at the Poconos home. They ditch the party and get wasted at her home. She asks them if she could reenact the night of the sleepover and hypnotize them. Everyone reluctantly agrees, and minutes later they wake up to find Ali gone and the door of the room locked. A letter is slid underneath, informing the girls of the horrible truth: The Alison that they had been friends with had been Courtney all along and the real Ali killed her.
Courtney was mentally unsound and wanted to be Ali so badly that she tried to drown her when they were children. One day, when she was home from the mental institute, Courtney stole Ali's ring and imitated her when she saw Spencer and the others sneaking into their backyard. Ali was sent to the new mental institute, the Preserve, in Courtney's place, and was forced to take her sister's messed up life. On the night of the sleepover, she spied on the girls, followed Courtney after her fight with Spencer, and killed her in revenge for taking her perfect life. She hates the girls for ruining her life and tries to kill them too by boarding up the entire home and setting it on fire. The girls, including Melissa, manage to escape, but no one knows whether Ali is alive. It's hinted that she might be, as Emily hears a faint giggle in the distance as she visits Courtney's grave in the evening.
By the end of Crushed, the Liars know that the Second "A", Alison, has had an accomplice the whole time, and that this accomplice is the Third "A". They believe that Alison did indeed survive the fire in the Poconos house, and thus that the Second and Third "A" are currently operating together to bring them down (and eventually kill them).
The helper is revealed to be Nick Maxwell.
Original A was the first "A". The "A" game began chronologically in "The First Secret". Her lairs were located at Room 2 of the Lost Woods Resort motel and she was also living under a motorhome rental. She began torturing Alison by sending her gifts, threats and soon attacking her while wearing a zombie costume. "A" continued to mess with Ali and her mother Jessica DiLaurentis, whom she believed it to be Spencer Hastings. After Alison's disappearance, "A" went away for a year but after the corpse of Bethany Young (believed to be Alison at the time) was found, she reemerged. "A" began sending the Liars messages about things only Alison knew about them and soon even began messing with their parents. Doctor Anne Sullivan had previously dealt with the person behind the hoodie and when "A" trashed her office she immediately recognized the person. She almost exposes her identity to the Liars but "A" kidnaps her and went as far as to threaten her son's life. But the Liars are still close to figuring it out and during the second half of season two they manage to get a hold of "A's" phone. They hatch a plan to catch her with this and it works. They find out that "A" had a lair at the Lost woods resort and Spencer and Mona ("A's" newest victim) head over there and find a room full of pictures of Alison and the girls along with a sketch of "A's" costume to the ball, The Black Swan. However, Spencer begins to notice other clues and soon realizes "A" is right there with her. She turns around to see Mona in a black hoodie, who reveals herself as "A". She kidnaps Spencer and gives her an opportunity to join the "A" team but Spencer declines and the two get into a fight, where Mona is pushed off of a cliff. Though Mona survives, she is sent to Radley Sanitarium for medical assistance. While in the psychiatric hospital, Mona takes up a partnership suggested by the then unknown CeCe Drake that starts off the second game. After this, Mona became another henchmen in the "A" hierarchy, obeying the orders of CeCe, whom she knew as Red Coat. Mona was kicked off of the A-Team in the season three finale.
Big A was the person who took over the "A" game from Mona Vanderwaal after she was admitted to Radley Sanitarium. For most of the third season Big A lurked in the shadows, letting Mona, Toby and Spencer (to a lesser extent) do the work for her, while she would sometimes overlook these missions as Red Coat. Their lairs were located at the apartment "A" building on Avenue Mayflower Hill and they also shared custody of an RV. However, the "A-Team" disbanded in "A dAngerous gAme" and Big A began working with a single ally and various minor minions. Big A, in her Red Coat disguise, began sneaking into the DiLaurentis home, where she would surveil the place. In the mid-season finale of the fourth season, it was revealed that there were two Red Coats and that one of them (later divulged to be Alison) was actually helping the Liars and on the run from "A". The "evil" Red Coat is revealed to be CeCe Drake, however the Liars are under the impression that someone is paying her. In "A is for Answers" the Liars are attacked in New York by someone who appears to be "A" and eventually shoots Ezra Fitz. In the following episode "EscApe from New York.", it is revealed that this person was Shana who explains that she turned on Alison after learning that she was responsible for Jenna's vision loss. She is then killed by Aria, who knocks her off a theater stage. After this incident, the Liars thought Shana was Big A and the real Big A took a break but returned in the 100th episode with a brand new lair, meaning that Shana was someone with an agenda unrelated to the "A" game. Inside the lair is the infamous dollhouse and her ally's Black Widow costume. In "Taking This One to the Grave.", Big A was thought to have murdered Mona Vanderwaal until she was revealed to be alive in the fifth season's finale "Welcome to the Dollhouse." In the very same episode, Big A kidnaps the Liars and holds them hostage for weeks in an underground bunker. It's there that Spencer discovers that the antagonist is seemingly named Charles DiLaurentis. He was revealed to have had a lair at the old Campbell farm basement near Wayne, Pennsylvania. In the sixth-season episode "Game Over, Charles" this "A" was revealed to be CeCe Drake, whose real name is Charlotte DiLaurentis. Charlotte was born as Charles and sent to Radley by her father at an early age due to identifying as a female, though her mother secretly helped her transition into a woman while she was a teenager. Charlotte hunted down the girls because she thought they were happy that Alison had presumably died and quickly became addicted to the feeling of power since she was neglected for most of her life. Charlotte also reveals that her ally was Sara Harvey, whom she had dress up as Red Coat and the Black Widow. After revealing her story, Charlotte attempts to blow up Radley with Sara's aid and the remaining DiLaurentis family in it, but her plan fails. She then tries to commit suicide by jumping off the roof of the sanitarium, but she's stopped by the girls and instead declares an ending to her reign as "A". Charlotte spent the subsequent five years at the Welby State Psychiatric Hospital and was eventually released after most of the Liars lied under oath so Alison could lead a happy life with her sister. However, the next morning shes's found dead after having been murdered and thrown off the local church's bell tower to make it seem like a suicide. This horrifying event lead to the rise of a new villain later baptized as "A.D.", who began stalking the Liars into divulging the identity of Charlotte's killer. It is revealed in the seventh season that Noel Kahn was working for Charlotte in the Dollhouse and placed the blood on Spencer for her. It is also revealed that Charlotte was friends with Jenna Marshall, and Jenna was possibly working on her A-Team.
Uber A is the third major "A" to have tormented the Liars. This antagonist desperately craves vengeance over the tragic passing of Charlotte DiLaurentis, and is trying to seek out the person responsible. Unlike Mona or Charlotte, this villain does not use any nicknames at first but instead signs their messages with emojis, which differentiates them from the A-Team. This causes Caleb to nickname them Amoji. However, in the sixth-season finale, they begin using the alias "A.D." and kidnap Hanna, whom they believe is accountable for their loved one's homicide. Hanna manages to escape Uber A's clutches and they go after Alison, who the Liars suggested as guilty for her own cousin's murder. Uber A eventually finds out that Alison is innocent after searching her jacket. While Uber A does work on their own, they also work through helpers, one of which is Jenna Marshall, though she is not aware of their identity.
The A-Team is a group of anonymous characters that worked together as "A". The team would work under the orders of the "A" in charge, who has been Mona Vanderwaal, the original leader and founder and CeCe Drake, the second leader.
Sara was the right-hand woman to Charlotte and also revealed as an A-Team member halfway throughout the sixth season. Sara is revealed as a Red Coat and the Black Widow, hired to pose as a decoy whenever Charlotte couldn't sport the Red Coat disguise. She then became Charlotte's friend and ally in the "A" game and assisted her in most of her schemes. Sara was allegedly diagnosed with Stockholm Syndrome following Charlotte's arrest, but later discloses to Alison that she lied under oath in order to reduce her criminal sentences while also admitting that she and Charlotte were in fact close friends.
Toby was recruited by Mona to join the A-Team when he got a job in Bucks County. His participation in the team was revealed in the mid-season finale of the third season. He worked hand in hand with Mona and did most of the dirty work for the team, like running down Lucas and attacking Hanna. However, like Mona, he didn't know the identity of Red Coat. Spencer finds out about his betrayal and goes off the deep end, especially after discovering his corpse. However, it is revealed that he is alive and well, with the corpse being a trick by Mona and Red Coat that he says he didn't know about until after. He is also revealed to be a double agent and gets kicked off the team.
Spencer joined the A-Team near the ending of the third season after having been invited by Mona at the Radley while hospitalized. Initially, Spencer was extremely determined to be part of the team. However, she later unfolds the truth behind the disappearance of Toby and became a double agent as well. Likewise Toby, she got kicked off from the team. She is the "A" who kidnapped Malcolm, causing a break up between Ezra and Aria.
Lucas was the personal assistant to Mona. He was blackmailed by Mona and the A-Team into sending texts and doing their dirty work. Lucas claims his blackmail began after Mona discovered he was selling test answers, however Mona later discloses that Lucas was the "A" who gave Emily a massage back in the second season while Mona was off riding with Hanna.
Melissa was blackmailed by Mona into wearing the Black Swan disguise to the Masquerade Ball in order to distract Jenna. Mona threatened to reveal her fake pregnancy if she didn't obey her orders. Later, Melissa got onto the Halloween Train dressed as the Queen of Hearts and drugged Aria. She and Wilden then attempted to push her off of the train in a box with Garrett's dead body. It is implied that she was once again blackmailed.
Wilden was also part of the team as he was the Queens of Hearts responsible for trying to kill Spencer. He also murdered Garrett Reynolds fearing he'd expose him as a crooked cop and placed his corpse in a box beside a fainted Aria. Wilden's reasoning for helping the team is unknown but implied to be blackmail.
Revealed in the seventh-season episode "Hit and Run, Run, Run", Jenna is working anonymously for "A.D." and also with Archer Dunhill in someway. She remains around Rosewood in "Along Comes Mary" and befriends Sara Harvey. Meanwhile, Aria Montgomery and Emily Fields discover that Jenna was on Archer's payroll for unknown reasons. On the episode's closing scene, Marshall and Sara are having drinks at The Radley when an unknown figure approaches the two and reveals themselves to be Noel Kahn, who proceeds to join the duo. When confronted by Emily in regards to her involvement with Archer during "Wanted: Dead or Alive", Jenna admits she befriended Charlotte DiLaurentis after reading about her stay at Welby and reached out. In a flashback, Charlotte enlists Jenna's help to track down the whereabouts of her birth mother and come up with an alias for Archer. The pseudonym "Elliott Rollins" was later created so Archer could deliberately meet Alison and take advantage of her good intentions to benefit Charlotte's eventual release from the psychiatric hospital. In "The DArkest Knight" all of the Liars get a text message, ordering them to head over to 1465, Elm Street. After being lured to an abandoned school for blind students, they're held hostage by Noel and Jenna, with Marshall tracking them down at gunpoint. During the cat-and-mouse chase, Jenna takes aim at the Liars only to backfire, until a second gunshot is heard and it injures Spencer. As Marshall prepares to finish her off, Mary Drake suddenly emerges from behind and knocks her out. While Drake attempts to help Spencer, an unknown figure drags Jenna away from the building. On the closing scene of the episode, the annonymous entity places her in the back of a van, while she questions them if they were responsible for the gunshot that hit Spencer. As the mysterious figure proceeds to rip off an old man's mask and toss it over to Jenna's side, Marshall feels it up and realizes that A.D. was the one who abducted her.
Revealed in "Along Comes Mary", Noel Kahn returned to Rosewood to team up with Jenna Marshall and Sara Harvey. Kahn served as one of Charlotte's former minions and worked for her at the Dollhouse, having been responsible for placing blood all over Spencer Hastings to convince she had hurt someone. Noel became the prime suspect for Uber A, particularly after Alison reveals that he pushed a girl down a flight of stairs when he was drunk during a UPenn frat party. Hanna abducts him at the end of "The Wrath of Kahn" in an attempt to obtain a video confession that proves he's their tormentor. In the following episode ""The DArkest Knight", she instead ends up slashing his leg with a knife in order to test his DNA and see if it matches Mary Drake's. The results later come back negative and Kahn ends up escaping. Noel and Jenna later lure the Liars to an abandoned school for blind students so they could be held hostage and eventually murdered. During a cat-and-mouse chase, Kahn ends up stumbling upon an axe that decapitates his head after failing to fight Emily and Hanna.
During the TV series, the antagonists used various disguises at parties and events, in order to watch over the girls. They are:
Red Coat is a disguise used by two members of the A-Team. CeCe Drake took on the disguise to lead the A-Team and go out in public, while she hired Sara Harvey to act as a decoy Red Coat to confuse the Liars.
The Black Widow is a previously anonymous character who attended detective Darren Wilden's funeral in "'A' Is for A-l-i-v-e". The disguise is mounted in a dark suit accompanied by a black veil, which hides her face. In the fifth season, the disguise is seen inside one of "A"'s lairs. Charlotte later revealed that she sent Sara Harvey to Wilden's funeral dressed up as the mysterious woman in black to make sure he was deceased.
In a nightmare that Alison had during "How the 'A' Stole Christmas", her mom, Jessica DiLaurentis shows up as the Black Widow.
The Queen of Hearts is a previously anonymous character that made an appearance during the third season's Halloween special, "This Is a Dark Ride". In the fourth season's premiere, it is revealed that there were actually two of them in the Halloween train, Melissa Hastings and Darren Wilden. Wilden attacked Spencer and fought Paige, while Melissa drugged Aria and took her body. Wilden also murdered Garrett Reynolds fearing he'd expose his corrupt activities and Melissa later admits to Spencer that she was blackmailed into doing his bidding. However, in Mona's footage, evidence shows that Wilden tried to abandon the train and Melissa is heard ordering him to stay. Wilden would later place a fainted Aria in a box beside Garrett's corpse and then gathered with Melissa in an attempt to push them off the train. They fled the scene once Aria regained her consciousness and stabbed Wilden.
The Black Swan is a previously anonymous character that made an appearance during the Masquerade Ball. Melissa was revealed to be the person behind the disguise in "Birds of a Feather". She claimed that "A" (Mona) threatened her, stating that her false pregnancy would've been exposed if she did not distract Jenna during the event. The disguise is inspired by Odile from Swan Lake.