Morlocks (X-Men (TV series))
The Morlocks appear in X-Men: The Animated Series. Its members are Callisto, Leech, Erg, Masque, Sunder, Plague, Annalee, Ape, Scaleface, Tommy, Tar Baby, Mole, Glowworm, and Caliban. They first appear in "Captive Hearts" where the Morlocks captured Cyclops and Jean Grey. The X-Men led by Storm then came to get Jean and Cyclops back. In the end after a duel between Storm and Callisto, not only did the X-Men get Cyclops and Jean back, Storm also gained leadership of the Morlocks. Several of the Morlocks would have subsequent cameos outside of the sewers (an example being "Sanctuary"). They would have a major role to play in the episode "Out of the Past" and were last seen in "Have Yourself a Morlock Little X-Mas".
Annalee
Annalee appeared in the X-Men episode "Captive Hearts" VOICED by Kay Tremblay. She seemed to have a greater control over her powers, causing the X-Men, including Jean Grey, to experience any state of mind she chose to place them in, from Wolverine believing himself to be covered with scorpions, to Jean believing herself to be a young child and Annalee her mother.
Ape
Ape appears in the X-Men episode "Captive Hearts" voiced by Ross Petty. He is among the featured Morlocks that fight the X-Men. In "Secrets Not Long Buried," Ape is one of the many residents of the mutant-dominated community of Skull Mesa. He is drawn twice in the scene where Cyclops walks through Skull Mesa alone.
Caliban
Caliban made a number of cameo appearances in the 1990s X-Men: The Animated Series, including the episode "Slave Island". He also appeared in the final season episode "The Fifth Horseman", in which Caliban had been transformed by Fabian Cortez into one of Apocalypse's Hounds (used in a similar role to the Horsemen), until Jubilee made Caliban turn against Cortez and the rest of the Hounds, who sought out a mutant to use as a new host body for Apocalypse's reincarnation. In this episode, Caliban was retconned into a member of the Morlocks, though he had never appeared in the episodes featuring the underground mutant community.
Callisto
Callisto appeared in X-Men: The Animated Series voiced by Susan Roman. She and the other Morlocks captured Cyclops and Jean Grey rather than Angel. In the Spanish-dubbed version of the show, Callisto is portrayed as a male character in the two-part episode Out of the Past. In the other episodes involving the Morlocks, Callisto is correctly voiced by a female Spanish actress.
Erg
Erg has appeared in a few episodes of the X-Men: The Animated Series with his fellow Morlocks and fought the X-Men.
Leech
Leech appears in a few episodes of the X-Men Animated Series, voiced by John Stocker. His most notable appearance was in the Christmas episode "Have Yourself a Morlock Little X-Mas" where he needed a blood transfusion from Wolverine, temporarily granting him Wolverine's healing ability in order to fight off a disease.
Mole
Mole first appeared in the X-Men episode "Captive Hearts." He was a member of the Morlocks. In "Secrets Not Long Buried," Mole is one of the many residents of the mutant-dominated community of Skull Mesa.
Plague
She appears in the X-Men animated series as a member of Apocalypse's Horsemen in the episode "Come the Apocalypse" as a woman wanting a cure then as Pestilence.
Sunder
Sunder appeared in the X-Men animated series alongside the Morlocks, exhibiting the same strength as the comics version. He was unable to stand up to Rogue, though. Later, in the episode "Secrets Not Long Buried," he is one of the many residents of the mutant-dominated community of Skull Mesa. He was played by Dan Hennessey.