The Wall of Flesh makes its first and only appearance in the episode "Tree Trunks," when Finn, Jake, and Tree Trunks step on it in its home in the Evil Forest. It soon rises up from the ground and barricades their path. Finn and Jake begin punching it with no effect while Tree Trunks, thinking the Wall of Flesh needs some "tender love and affection," puts stickers on it: a rainbow, a scratch-and-sniff pickle, and a holographic horse which she refers to as "a unicorn without a horn." The Wall of Flesh gets angry and picks up Tree Trunks, preparing to eat her. Finn notices this and slices off the Wall's arm, saving Tree Trunks. The Wall of Flesh melts and retreats into a tree while whimpering.
The Wall of Flesh is a pile of flesh that can form itself into a wall with a floor. It has two eyes, one next to its mouth and the other on the part of the creature that is on the ground. It also has one mouth. It is peach-colored, like flesh.
- The Wall of Flesh was the answer to one of Gaia Online's ten trivia contests to answer to try to win a first season DVD set.
- There is a boss in the game Terraria of the same name.
- The Wall of Flesh and the Sign Zombies make an appearance in the game Rock Bandits, reacting negatively to the performance of the Ice King's band.