Sewer King is a supervillain that appeared in the Batman : The Animated Series episode "The Underdwellers". He keeps abandoned children as slaves and abuses them. He is voiced by Michael Pataki.
Sewer King took in Gotham City's abandoned children and lived underground. He subjected them to constant abuse and an authoritative lifestyle. They soon were molded into his slaves, unable to speak or act without his command. The Sewer King then forced the children to roam the streets of Gotham and pick pocket, at night. Batman encountered and captured one of the children, Frog. With Frog's help, Batman uncovered the King's operation and confronted him. After wrestling his trained crocodiles, Batman defeated the Sewer King and turned the children over to the police for adoption.