Spider-Man: The Animated Series 1x1

Peter Parker and his college science professor Dr. Curt Conners explore neogenics as a method of limb regeneration. But while experimenting on himself, Connors accidentally becomes the Lizard, a half-man, half-reptile monstrosity that terrorizes Manhattan and subsequently kidnaps his own wife. Spider-Man must stop the Lizard, but his task is doubly difficult because he doesn't want to hurt the good friend he knows is trapped inside.