Invader ZIM (2001)

Season 1: Episode 20

When Dib once again notices that Zim isn’t eating his food, he throws a piece of bologna at him in order to taunt him, in which the bologna fuses with Zim’s skin, causing him immense pain. Zim vows to get his revenge and during the next day of school, Dib sits on a tack, which causes Zim to begin laughing hysterically. Dib believes Zim is just being pathetic, but when Dib begins to transform into a living piece of bologna, he realizes that Zim’s plan was better than he had thought and he must formulate a method of curing himself before it’s too late.