Archie's Weird Mysteries - Season 1 Episode 22 It Lives in the Sewers
Overview: Yesterday, Jughead lost his pet baby alligator Peanuts when Veronica flushed the poor thing down into the sewers; Jughead has been in mourning ever since. Today, there is a mysterious monster in the sewers, grown abnormally large from a toxic waste spill. Coincidence...?