Corpse

Corpse is a new environment added in Antibirth.

Once all three knife pieces have been acquired, upon completing Mausoleum II, a red fleshy door will appear. Stabbing the door with the knife will open it, leading to a more difficult variant of Mom's Heart. After defeating Mom's Heart, the trapdoor previously leading to the Womb will now lead to the Corpse.

Monsters

Monster	Description
Adult Leech	Charges towards Isaac when he's in their line of sight, and burrows in the ground to either pop out the side of the wall or the ceiling.
Barfy	Wanders around the room, and slowly follows Isaac when he's in its line of sight. Occasionally spews clusters of green shots towards Isaac.
Cohort	Hops around, occasionally stopping to spew out a cluster of blood shots at Isaac. Upon death, spawns four Globins.
Coil	Creates beams of electricity to other enemies in the room. Touching the electricity damages Isaac. Cannot be killed.
Cyst	Attaches itself to a wall or obstacle and rolls around it while periodically firing blood shots at Isaac.
Evis	Spits outs its guts, which latch onto Isaac, dealing no damage but slowly drawing Isaac closer to it, impeding movement.
Gasbag	Continuously creates a gas cloud around them.
Mama Fly	Lays Pustules on the ground. Explodes into Small Maggots when killed.
Pustule	Grows until it bursts into Small Maggots, and leaves a small puddle of green creep.
Rotten Gaper	Chases down Isaac, and may explode into Small Maggots.
Sick Boom Fly	Flies around the room diagonally. Upon death, creates a large poison cloud.
Small Maggot	Slowly crawls around the room randomly.
Spikeball	Travels back and forth in a straight line across a room. Cannot be killed.
Stillborn	Slowly floats towards Isaac, occasionally firing blood shots. Cannot be killed and dies when the room is cleared.
Twitchy	Alternates between chasing Isaac and leaping at him.
Vessel	Walks around the room and explodes into Small Maggots upon death.
Unborn	Spins and floats around the room towards Isaac, and can teleport randomly.