Mammoth first appeared in New Teen Titans #3 and was created by Marv Wolfman and George Pérez.
Mammoth is one of the founding members of the Fearsome Five, and became enemy of the Teen Titans, Superman, and the Outsiders. He is highly devoted to his sister Selinda (a.k.a. Shimmer), also a founding member of the Fearsome Five. A towering hulk of a man with immense physical strength and durability, Mammoth is intellectually and emotionally underdeveloped (so much so that he was once tricked into surrendering to a Superman whose powers had recently been lost thanks to Lex Luthor's use of Mister Mxyzptlk's red kryptonite thanks to Superman simply faking confidence that he could defeat Mammoth), and he lacks skill as a hand-to-hand combatant.
Mammoth at one point retired to a Tibetan monastery along with his sister although shortly thereafter discovered Psimon (himself a former member of the Fearsome Five). Psimon used his mental abilities to subdue Mammoth and turn Shimmer into glass, which he then proceeded to shatter in an act of vengeance. Mammoth subsequently works with former ally Gizmo, apparently unable to comprehend his sister was dead, and believing they were looking for her.
Mammoth later appears in a fight with Booster Gold, which he loses. He is surprised at being found out, as his crime was a spur-of-the-moment deal (he did not understand Gold has access to future information).
Mammoth alongside his Fearsome Five teammates appeared as members of the Alexander Luthor, Jr.'s Secret Society of Super Villains.
On the cover of Justice League of America #13 (Vol. 2), it shows Mammoth as a member of the new Injustice League and is one of the villains featured in Salvation Run. He is one of the villains sent to retrieve the Get Out of Hell free card from the Secret Six.
Mammoth later appeared as a member of Cheetah's Secret Society of Super Villains. He was among the villains in the ambush of the JSA led by Tapeworm.
Mammoth later appeared as a member of the revived Fearsome Five when his sister breaks him out of jail, while he was trying to read to increase his intelligence, though, this only gives him words that do not fit the sentences they are in. His new-found "intelligence" does not quell his need to kill others, as he frequently suggests killing Wonder Girl while they have her bound in her own Lasso.
Mammoth is later shown in the employ of Calculator, and is hired to capture the members of the Birds of Prey while they are celebrating at a male strip club.
In The New 52 (a reboot of the DC Comics universe), Mammoth first appeared as a member of the Fearsome Five. The group is shown as part of the Secret Society, which were working with the Crime Syndicate. Mammoth was sent by Grid with the other members if the Fearsome Five, Jinx, Gizmo, Shimmer, Psimon, among Doctor Psycho and Hector Hammond where they had to fight against Cyborg and The Metal Men. He ends up defeated by Lead.
Mammoth later appears where he is trying to kill Nightwing, Donna Troy and Garth. He is beaten by a teamwork punch by Garth and Donna Troy.
Mammoth possesses superhuman strength and durability, including a degree of protection from energy attacks.
In JLA/Avengers #3, Mammoth appears as part of a group of villains who attack the Vision and Aquaman in Metropolis. He is blasted by the Vision, but is finally knocked out by Thor and restrained by Green Lantern]].
Mammoth makes appearances with his fellow students in the Teen Titans Go! comic book series.Mammoth appears in the Teen Titans animated series, voiced by Kevin Michael Richardson, as a member of the former H.I.V.E. Academy. Mammoth is depicted as a class bully who is very strong but lacking in intelligence. He later forms The H.I.V.E. F.I.V.E. with the Jinx, Gizmo, See-More and Private H.I.V.E. He appears in episodes including "Titans Together".
Mammoth appears in Young Justice. In "Drop Zone", he and his sister Shimmer are reimagined as enforcers for Kobra's drug-producing operations. Unlike the comics where Mammoth is described as having been born with his abilities, here he is portrayed as a scrawny teenager who gains his monstrous strength and appearance from a combination of the Venom steroid and the Blockbuster formula being injected into his body. Though he is shown to be powerful enough to easily trounce Bane and Superboy in combat, he is ultimately defeated after being electrocuted into unconsciousness by Aqualad. He later appears in the episode "Terrors" where he is shown as an inmate at Belle Reve, acting as a bodyguard for Icicle Sr. and other high ranking prisoners. He assists in a breakout attempt orchestrated by Mr. Freeze, but is defeated by the combined efforts of Superboy and Icicle Jr. He later appears in "Usual Suspects", "Beneath" and "Intervention".
Kevin Michael Richardson reprises his role as Mammoth in the Teen Titans Go! series. He debuts in the episode "Gorilla" where the Titans are fighting him. Robin asks Beast Boy (in his gorilla form) for help, but refuses and Mammoth escapes. In the episode "H.I.V.E. Five," Mammoth is shown doing some breakdancing at the time when the H.I.V.E. Five are taking a day off from their evil activities. Upon being defeated in a dance-off, Mammoth briefly say "Beast Boy" in anger. His next speaking appearance isn't until the episode "Scary Figure Dance".
Mammoth is also a boss in both Teen Titans video games: the console version and the GBA version.
Mammoth appears in DC Universe Online as part of the "Sons of Trigon" downloadable content.