Corpse

The Corpse is a new floor added in The Binding of Isaac: Repentance, which acts as the Womb's alternative Chapter. It features a desolate and dreary atmosphere with enemies that carry the theme of death and advanced rot. The Corpse is one of five final levels in The Binding of Isaac, alongside the Chest, the Dark Room, The Void, and Home.

To access The Corpse, the player must first open the flesh door at the end of the Mausoleum/Gehenna II after defeating the Mausoleum version of Mom by doing one of the following:

Collect Knife Piece 1 and Knife Piece 2, which are obtained via puzzles inside Downpour and the Mines, to build the knife familiar, and stab the door with it.
Sacrifice one key and open the door by using Sharp Key.
Cracked Orb can also open the door while simultaneously letting you keep the knife familiar.
Using a Soul of Cain.
If Isaac exits the Boss Rush room in Gehenna after 25 minutes have passed, there is a chance that the flesh door will change positions to the wall where the boss rush door was, causing Isaac to "come out" of the flesh door and leaving it open, allowing entry without the knife.

On the other side of the flesh door, the player will fight the Mausoleum version of Mom's Heart, after which the entrance to the Womb will turn into the Corpse entrance, which will take the player into the Corpse floor.

The boss of Corpse II is always Mother.

Monsters

Entity	ID	Description
Wrinkly Baby	38.3	Dashes towards Isaac at high speed and fires three blood shots in his direction once stopped.
Unborn	860.0	Floats quickly towards Isaac, and occasionally teleports to another position near him.
Pustule	861.0	Slowly increases in size over time, spawning Small Maggots and damaging red creep depending on its size upon death. If it grows to full size, it transforms into a Bloodfly.
Poison Mind	301.0	Slowly crawls/floats around the room diagonally, leaving a trail of damaging green creep. Explodes upon death.
Gutted Fatty	831.0	Slowly lumbers around the room, occasionally spawning Festering Guts. Its eyes dislocate as it takes damage, which are invincible and follow the Gutted Fatty but chase Isaac if he gets close to them. Creates a geyser of blood projectiles upon death.
Army Fly	868.0	Chases Isaac, moving along the cardinal directions. Forms a line with other Army Flies in the room. Deals contact damage.
Sick Boom Fly	25.5	Flies across the room in straight diagonal lines, dealing contact damage and trailing poisonous gas. Upon death, explodes into a gas cloud and fires a ring of 6 green shots.
Mama Fly	61.4	Flies more-or-less away from Isaac, occasionally plopping on the ground to plant a Pustule. Upon death, they spawn a group of Small Maggots.
Rotten Gaper	10.3	Walks toward Isaac, dealing contact damage. Its behavior varies slightly depending on its facial expression.
Twitchy	851.0	Alternates between walking towards and rapidly leaping at Isaac, dealing contact damage. Can leap to Isaac's current position, or where Isaac is heading, and can also leap away to dodge incoming fire.
Level 2 Gaper	850.0	Walks towards Isaac, dealing a full Heart of contact damage. Splits into a Level 2 Horf and Level 2 Gusher upon death.
Level 2 Horf	850.1	Slowly floats toward Isaac, spitting Small Maggots at him.
Level 2 Gusher	850.2	Runs aimlessly around the room, spitting up Small Maggots.
Gasbag	856.0	Occasionally summons Army Flies to chase Isaac. Is surrounded by a ring of toxic gas that hurts Isaac if he stands in it for too long.
Globin	24.0	Chases Isaac, dealing a full heart of contact damage. Upon taking enough damage, it collapses into a pile of goo, which can be killed. Will regenerate after a short period of time if not killed quickly.
Gazing Globin	24.1	Quickly chases Isaac, dealing a full heart of contact damage. Upon taking enough damage, it collapses into a pile of goo, which will slide away from Isaac and can be killed. Will regenerate after a short period of time if not killed quickly.
Cohort	857.0	Acts similarly to Monstro, hopping towards Isaac and can either spit a large projectile towards Isaac that bursts into 8 smaller projectiles or cough up a burst of arcing projectiles and a pile of Globin goo. Spawns 4 piles of Globin goo upon death.
Cyst	862.0	Attaches itself to a wall or obstacle and rolls around it, regularly firing blood shots at Isaac.
Dead Meat	57.2	Slowly moves around the room, occasionally hopping and firing 8 large blood shots in all directions that bounce off the walls. Splits into 2 Cysts upon death.
Eggy	29.2	Hops aimlessly around the room, spawning slowing white creep wherever it hops. Spawns a group of Swarm Spiders upon death.
Leech	55.0	Quickly charges towards Isaac when he gets in its line of sight.
Adult Leech	854.0	Wanders around the room, quickly charging at Isaac when he lines up horizontally with him and releasing a ring of blood shots upon colliding with a wall. After taking a certain amount of damage, burrows into the ground and reappears by falling above Isaac, releasing another ring of blood shots and only performing this behavior once.
Maggot	21.0	Aimlessly moves around the room, dealing contact damage.
Small Maggot	853.0	Slowly crawls toward Isaac, dealing contact damage.
Charger	23.0	Slowly moves around the room, charging at Isaac when he gets in its line of sight.
Level 2 Charger	855.0	Slowly moves around the room, charging at Isaac when he gets in its line of sight. Can slowly change its trajectory while charging.
Floast	859.0	Floats diagonally around the room and is normally invulnerable. When Isaac gets close, reveals a fleshy stem that can be damaged and fires 3 blood shots in an angle at him before hiding its stem again.
Evis	865.0	Randomly wanders around the room. Launches a string of guts when Isaac gets close to it, which it uses to pull Isaac toward itself.
Stone Grimace	42.0	Stationary and invulnerable monster that occasionally fires a blood shot at Isaac. Stops firing when room is cleared.
Triple Grimace	42.2	Stationary and invulnerable monster that occasionally fires a triple shot at Isaac. Stops firing when room is cleared.
Wall Hugger	218.0	Moves around the room like Guts, damaging Isaac by contact. Cannot be destroyed.
Spikeball	852.0	Spike balls that fly in a line either horizontally or vertically, bouncing off walls and obstacles.

Degraded Bosses:

Name	ID	Notes
The Bloat	68.1
The Cage	265.0
Carrion Queen	28.2
Chub	28.0
Fistula	71.0
The Frail	62.2
The Gate	263.0
Gluttony	49.0
The Husk	67.1
Monstro II	43.0
Pestilence	64.0
The Pile	269.1
Polycephalus	269.0
Sloth	46.0
The Stain	401.0
Super Gluttony	49.1
Super Sloth	46.1
Teratoma	71.1	All forms.

Bosses


The Scourge	Rotgut	Chimera	Mother

Notes

Mama Mega! can not be used to open the Flesh Door.
We Need To Go Deeper! and Rune of Ehwaz cannot generate trapdoors in Corpse II.
An I AM ERROR room can only be visited in Corpse II via clipping out of a Crawl Space; such an I AM ERROR room will contain a passageway which leads back to the starting room of the floor.
If the game is exited after defeating Mother and rejoined, there will be a door in the room allowing the player to leave the room. This can be used to go to a Sacrifice Room and then warp to the Dark Room, letting the run continue further.

Trivia

The Corpse is the only Alternative Chapter to not have any alternative floors.
- An unused floor named Mortis, presumably as an alternative to the Corpse, exists in the game files.
In Antibirth, the hole to the Mother battle had 4 Locked Chests next to it that always contained items, similar to chests in Chest.
If a room's floor is filled with blood, there will be a huge blood stain on the floor upon entering any room adjacent to it.