Caliban

Caliban made a number of cameo appearances in X-Men, 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.

Powers
Caliban's mutant power allows him to psionically sense other mutants out to several miles and track their movements. Cortez made him bigger and gifted with superhuman strenght.