The duel between Storm and Callisto was a lot more violent in the comic. Instead of the cartoon's high-tech quarter-staffs, the comic duel was a knife fight, ending with Storm stabbing Callisto in the heart (she survived thanks to a Morlock healer).
This episode is based on a two-parter story that appeared in "The Uncanny X-Men" (Vol.1) #169-170, written by Chris Claremont and drawn by Paul Smith, which introduced Callisto and the Morlocks, a group of outcasts some mutants living in the sewers of Manhattan. The similarities between this episode and comic are: the plot revolves around the team rescuing a kidnapped member, Storm is in the rescue party, An X-Man gets infected by the Morlock mutant Plague and Storm fights a duel with Callisto, wins, and becomes Morlock leader.
In the original comic book version of this story, Storm had a rougher experience than her comic book counterpart. She received a blow to the head thanks to a sling-shot metal ball (courtesy of Callisto), gets infected by Plague (swiftly recovers thanks to a unique immunity system in her body), and a slash on the arm and cheek in her duel with Callisto. At this point of the comic, she had also been able to withstand her claustrophobia, a recovery that would have been impossible in the cartoon, seeing how the fear was introduced in the previous episode.
While Scott and Jean are on their date, Leech is seen stealing fruit using telekinesis. In the comics, Leech does not posses telekinetic powers. Aside from his green appearance, Leech's mutation only gives him the ability to cancel out other mutant's active abilities.
The morlocks kidnapped Scott Summers and Jean Grey who were out on a date. In the comic, the kidnapped victim was Angel (then an inactive member), to be made Callisto's consort.