Wall of Flesh

The Wall of Flesh is a Stage Hazard exclusive to Chapter 8: The Penthouse.

Appearance
It is a massive wall of red meat-like material that has multiple needles and snapping maws of hooked teeth growing out of it, as well as gaping holes in it.

Description
It appears in a hallucination scene the midsection of The Penthouse, and chases down the protagonists through a hallway of hallucinatory doors of bone & meat, which need to be destroyed to reach the end of the hallucination and escape it.

Two of them also appear during Nekro's first phase, and close in on the player. To destroy them, the protagonists need to throw syringes provided by Shadows at them.

Trivia

 * It bears a resemblance to a Terraria boss of the same name, and may in fact be inspired by it.