TMNT Season 4 Episode 23 - Adventures in Turtle Sitting Episode Title:Adventures in Turtle Sitting.Episode Description:The Turtles continue to deal with the seemingly unstoppable mutant outbreak, but they leave Donatello under care of April and Casey when he becomes very ill. However, Donnie's illness is not just a cold; he is in the final stages of a secondary mutation that will transform him into a savage beast, to which the other turtles and Leatherhead must work together to capture. Meanwhile, Bishop recovers Stockman's brain from the bottom of the East River and resurrects Stockman giving him the half monster, half cyborg body.