The Underdwellers is the sixth episode of Season 1 of Batman : The Animated Series. The main antagonist of this episode is Sewer King. This episode originally aired on October 21st, 1992.
Batman encounters mysterious 'wee green people,' who have been committing petty crimes. He saves one and soon learns the boy belongs to a gang of forgotten runaways who live deep within the Gotham sewer system. Their leader, the crazed Sewer King, forces the children to steal food and supplies for him.
Alfred Pennyworth - Efrem Zimbalist Jr.
Matron - Victoria Carroll
Sewer King - Michael Pataki