The Catacombs

The Catacombs is an alternate chapter added with the Wrath of the Lamb expansion. Its appearance is similar to the Caves, but has pillars and cobwebs on the walls, as well as stones in the ground.

Rooms[]

1: The room will always appear once in this floor
2: The room will always appear twice in this floor
Possible: There is a chance for this room to appear, usually due to certain criteria being met
-: The room cannot appear in this floor.

Rooms	Catacombs 1	Catacombs 2	Catacombs XL	Note
Rooms from the core game
Regular Rooms	9 - 11	13 - 14	21-25
Treasure Room	1	1	2
Shop	1	1	1	There is always one shop, even in XL floors.
Secret Room	1	1	1
Boss Room	1	1	2	Boss Rooms are always linked in XL floors.
Challenge Room	Possible	Possible	Possible	Will only be generated if Isaac has full health while entering the floor.
Arcade	Possible	Possible	Possible	Only generated when Isaac has 5 Coins upon entering a new floor or part.
Devil Room	Possible	Possible	Possible
I AM ERROR	Possible	Possible	Possible	Only reachable by using the Telepills, which have a 6.66% chance to teleport Isaac to this room.
Rooms with Wrath of the Lamb
Rooms	Catacombs 1	Catacombs 2	Catacombs XL	Note
Super Secret Room	1	1	1
Curse Room	Possible	Possible	Possible
Sacrifice Room	Possible	Possible	Possible
Angel Room	Possible	Possible	Possible
Library	Possible	Possible	Possible	5% base chance to spawn, 25% if Isaac is holding a book.
Boss Challenge Room	Possible	Possible	Possible

Monsters[]

Monster	Description	WotL DLC
Eternal Fly	Invulnerable Fly that circles Corny Poop, Holy Leeches or Hangers.	✔
Fat Fly	Alternate version of Pooters. Fires 2 shots in a V-formation and does not deal touch damage.	✔
Red Boom Fly	Flies around the room diagonally, dealing touch damage and exploding into 6 directional blood shots upon death.
Spider	Moves erratically around the room, damaging Isaac by touch.	✔
Big Spider	Moves erratically around the room, splitting into two Spiders upon death.	✔
Trite	Quickly jumps towards Isaac with high distance.	✔
Gut	Stationary enemy that shrinks upon being hit. Will quickly swell up if not killed in time. Fires an IPECAC shot at Isaac when fully swollen.	✔
Sack	Stationary enemy that shrinks upon being hit. Swells up slower than Guts and Boils. Spawns a Spider when fully swollen.	✔
Walking Boil	Mobile Boil that cannot shrink, but has a finite amount of health. Fires short-ranged blood shots with varying sizes at a reduced fire rate.	✔
Walking Gut	Mobile Gut that cannot shrink, but has a finite amount of health. Fires IPECAC shots at a reduced fire rate.	✔
Walking Sack	Mobile Sack that cannot shrink, but has a finite amount of health. Spawns Spiders.	✔
Gurgle	Slowly walks towards Isaac, firing short-ranged IPECAC shots at him. Has much more health than regular Gapers.	✔
Knight	Moves erratically around the room. Can only be damaged from behind.
Clot	Moves around the room, firing 4 tar shots in an X pattern.
B. Licker	Attaches itself to other B. Lickers, erratically moving around the room, similar to Larry Jr.	✔
Chubber	Fires a Little Chubby-like familiar that deals one heart of damage when Isaac gets in its line of sight.	✔
Keeper	Hops around the room, firing 2 blood shots in a V formation at Isaac.	✔
Red Host	Stationary enemy that can be damaged even when its head is lowered. Fires 5 blood shots instead of 3 when rising, and fires more frequently.
Bosses found in normal rooms:
Fistula	Floats around the room diagonally, splitting into smaller, faster versions every time it takes damage. Smallest versions spawn a Charger when killed.

Bosses[]

Room-Layouts[]

Original

Trivia[]

In real life, Catacombs are human-made subterranean passageways for religious practice.

Chapters

Chapter 1	Chapter 2	Chapter 3	Chapter 4	Chapter 5	Chapter 6
The Basement The Cellar	The Caves The Catacombs	The Depths Necropolis	The Womb Utero	Sheol Cathedral	The Chest