The Sign Zombies (or Evil Sign Posts) appear in the episode “Tree Trunks” in which Tree Trunks goes off on her own, and is then attacked by these deadly creatures. When Finn and Jake finally manage to find Tree Trunks, she is surrounded by them but does not notice, setting out a picnic for them. When they attack, she thinks that this is because they want lots of food. Finn attempts to defend Tree Trunks, fighting them yet they scratch his face and, revealed in the aftermath of the battle, clearly seem to hurt him. Jake then attacks and defeats these Sign Zombies by zooming across and knocking them all out of the way. They get their name “Evil Sign Posts” from Finn when he sees those attacking Tree Trunks.