Catacombs

The Catacombs is one of the environments of Chapter 2.

The Catacombs are unlocked once each boss in the Caves has been defeated. It generally possesses more spiders and decayed enemies/bosses than the caves, like gurgles or guts.

After A Secret Exit is unlocked, a boarded door similar to the one leading to a Bedroom will appear in this floor's Boss Room upon defeating the boss, leading to the Mines / Ashpit. This door, like a Bedroom, requires two bombs to be opened. Unlike Angel Rooms and Devil Rooms, this door never disappears.

Monsters[]

Entity	ID	Description
Boil	30.0	Stationary enemy that decreases in size when hit, but regenerates to its full size until fully destroyed. Fires multiple short-ranged blood projectiles in random directions when fully swollen.
Gut	30.1	Stationary enemy that decreases in size when hit, but regenerates to its full size until fully destroyed. Fires Ipecac shots in random directions when fully swollen.
Sack	30.2	Stationary enemy that decreases in size when hit, but regenerates to its full size until fully destroyed. Occasionally spawns Spiders when fully swollen.
Walking Boil	88.0	Does not shrink or regenerate. Walks around aimlessly and fires multiple short-ranged blood projectiles in random directions.
Walking Gut	88.1	Does not shrink or regenerate. Walks around aimlessly and fires Ipecac shots in random directions.
Walking Sack	88.2	Does not shrink or regenerate. Walks around aimlessly and occasionally spawns Spiders.
Bony	227.0	Wanders around the room and throws a bone at Isaac when he is in sight.
Buttlicker	89.0	Can start attached to other Buttlickers and erratically moves around the room, similar to Larry Jr..
Chubber	39.2	Randomly wanders around the room. Pauses to fire a Charger that deals one heart of damage when Isaac gets in its line of sight. The Charger is invulnerable, blocks Isaac's tears, has limited range, and flies back to the Chubber.
Clotty	15.0	Randomly wanders around the room, firing 4 blood shots in the cardinal directions.
Clot	15.1	Randomly wanders around the room, firing 4 tar shots in the ordinal directions.
I.Blob	15.2	Randomly wanders around the room, firing 8 shots in all directions.
Dip	217.0	Slowly dashes in random directions, dealing contact damage.
Squirt	220.0	Dashes towards Isaac and deals contact damage. Spawns 2 Dips upon death.
Ring Fly	222.0	Gathers with any other Ring Flies in the room. These flies orbit around themselves while following Isaac. Deals contact damage.
Embryo	77.0	Aimlessly hops around the room, dealing contact damage.
Fatty	208.0	Slowly walks towards Isaac. Occasionally farts, which pushes Isaac and adjacent enemies away.
Pale Fatty	208.1	Slowly walks towards Isaac. Occasionally farts and shoots 6 blood shots in all directions. Has a chance to turn into a Blubber upon death.
Fat Sack	209.0	Slowly walks towards Isaac. Occasionally leaps off-screen and attempts to land on Isaac, leaving a puddle of Red Creep and shooting 6 blood shots in all directions where it lands. Has a chance to turn into a Blubber upon death.
Half Sack	211.0	Wanders around aimlessly and leaves a trail of Red Creep.
Blubber	210.0	Walks around aimlessly and randomly spews a cluster of blood shots in all directions. Has a chance to turn into a Half Sack when killed.
Fly	13.0	Hovers in place. Does not deal contact damage and is harmless, but can turn into Pooters if they stay around Poop.
Attack Fly	18.0	Red fly that follows Isaac and deals contact damage.
Moter	80.0	Follows Isaac, similar to Attack Flies. Deals contact damage. Splits into 2 Attack Flies upon death.
Level 2 Fly	214.0	Flies toward Isaac erratically, dealing contact damage.
Pooter	14.0	Slowly drifts toward Isaac, occasionally firing a single blood shot at him. Does not deal contact damage.
Super Pooter	14.1	Slowly drifts toward Isaac, occasionally firing two blood shots in a V-formation at him. Does not deal contact damage.
Boom Fly	25.0	Flies across the room in straight diagonal lines, dealing contact damage. Explodes upon death.
Red Boom Fly	25.1	Flies across the room in straight diagonal lines, dealing contact damage. Creates a ring of 6 blood shots upon death.
Full Fly	249.0	Flies toward Isaac erratically, dealing contact damage. Releases 6 bullets in all directions upon death.
Sucker	61.0	Flies slowly towards Isaac, exploding into 4 shots in the cardinal directions upon death.
Spit	61.1	Flies slowly towards Isaac, firing an Ipecac shot towards Isaac upon death.
Gurgle	87.0	Walks towards Isaac, dealing contact damage and periodically firing Ipecac shots at him; they are immune to this explosion, but other enemies are not. Can turn into a Splasher upon death.
Skinny	226.0	Slowly walks towards Isaac, leaving short-lasting Red Creep behind itself.
Rotty	226.1	Slowly walks towards Isaac, leaving short-lasting Red Creep behind itself. Spawns a Bony or two Attack Flies upon death.
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.
Grub	239.0	Erratically moves around the room like Larry Jr. and charges at Isaac when he gets within its line of sight. Spawns Maggots, Chargers, or Spitties upon death, one for each of its segments.
Gurgling	237.0	Charges towards Isaac when he lines up with them, leaving a trail of Red Creep and shooting 6 blood shots.
Psychic Horf	248.0	Stationary enemy that fires a homing shot at Isaac when he gets in range of them.
Flaming Hopper	54.0	Quickly hops around the room, doing contact damage. Covers a larger distance than the regular Hopper.
Hopper	29.0	Slowly hops around the room, doing contact damage. Can turn into a Flaming Hopper by jumping into Fire Places or other fires.
Leaper	34.0	Hops around the room, doing contact damage. Occasionally jumps high into the air, dropping down onto Isaac's position while firing 4 blood shots in the cardinal directions.
Host	27.0	Stationary enemy that is normally invulnerable. Raises its head up when Isaac gets close, revealing a fleshy stem that can be damaged. Upon raising its head, it will fire 3 blood shots in a spread and lower its head again.
Red Host	27.1	Stationary enemy that can be damaged even when its head is lowered. Fire 5 spread blood shots when it raises its head.
Mobile Host	204.0	Acts like the Host, but follows Isaac and deals contact damage.
Flesh Mobile Host	247.0	Acts like the Red Host, but follows Isaac and deals contact damage.
Keeper	86.0	Hops around the room, firing 2 blood shots in a V formation at Isaac. Upon damaging Isaac, Isaac drops 2 coins on the ground but loses 3.
Hanger	90.0	Floats around the room, firing 3 spread blood shots at Isaac. Upon damaging Isaac, Isaac drops 2 coins on the ground but loses 3. Spawns with an Eternal Fly circling around it.
Knight	41.0	Moves erratically around the room and charges towards Isaac when in line of sight. Can only be damaged from behind.
Maggot	21.0	Aimlessly moves around the room, dealing contact damage.
Charger	23.0	Slowly moves around the room, charging at Isaac when he gets in its line of sight.
Spitty	31.0	Slowly moves around the room, occasionally firing a single blood shot forward.
Conjoined Spitty	243.0	Slowly moves around the room, occasionally firing a blood shot from both ends of its body.
Mask + Heart	93.0	The Mask is invulnerable and moves around erratically, charging at Isaac when he lines up with it. The Heart avoids Isaac and fires 4 blood shots in the cardinal directions when Isaac gets near. Killing the Heart will automatically kill the Mask.
Maw	26.0	Slowly floats towards Isaac, firing a blood shot at him when he is in their range.
Red Maw	26.1	Floats quickly towards Isaac and releases 4 blood shots in the cardinal directions upon death.
Mulliboom	16.2	Chases Isaac and explodes upon death or upon touching Isaac. The explosion deals a half-heart of damage instead of the regular full heart.
Hive	22.0	Wanders around the room, avoiding Isaac and spawning Attack Flies if he gets close. Spawns a large number of flies on death, which can be Flies, Attack Flies, and/or Pooters.
Nest	205.0	Wanders around the room, avoiding Isaac and spawning Spiders if he gets close. Spawns a Big Spider or Trite upon death.
One Tooth	234.0	Follows Isaac and periodically dashes towards him when it gets close. Deals contact damage.
Splasher	238.0	Walks aimlessly around the room, firing Ipecac shots in random directions.
Round Worm	244.0	Pops out of the ground in random locations and spits a blood shot at Isaac if he is in sight.
Night Crawler	255.0	Pops out of the ground in random locations and fires four short-range shots that spiral outwards if Isaac is in sight.
Spider	85.0	Erratically moves around the room. If Isaac gets close to it, it chases him, trying to deal contact damage.
Big Spider	94.0	Erratically moves around the room. If Isaac gets close to it, it chases him, trying to deal contact damage. Spawns two Spiders upon death.
Level 2 Spider	215.0	Crawls around the room erratically, following Isaac and dealing contact damage. Can jump small distances.
Ticking Spider	250.0	Crawls around the room erratically, following Isaac and dealing contact damage. Can jump small distances. Explodes upon death.
Trite	29.1	Quickly leaps towards Isaac and deals contact damage.
Ragling	246.0	Quickly leaps towards Isaac and deals contact damage. Randomly shoots two purple shots that orbit around it.
Baby Long Legs	206.0	Runs away from Isaac and frequently spawns Spiders.
Small Baby Long Legs	206.1	Runs away from Isaac and occasionally spawns Sacks.
Crazy Long Legs	207.0	Chases Isaac, dealing touch damage. Occasionally stops to spit 8 blood shots in all directions.
Small Crazy Long Legs	207.1	Chases Isaac, dealing touch damage. Occasionally stops to spit 4 blood shots in the diagonal directions.
Wall Creep	240.0	Crawls along walls to try to line up with Isaac and shoots three blood shots in a line.
Blind Creep	242.0	Randomly crawls along walls and shoots three spread blood shots.
Tumor	229.0	Moves around the room diagonally, occasionally firing 6 blood shots in all directions. Fires more often upon getting damaged.
Stone Grimace	42.0	Stationary and invulnerable monster that occasionally fires a blood shot at Isaac. Stops firing when room is cleared.
Vomit Grimace	42.1	Stationary and invulnerable monster that occasionally fires an Ipecac shot at Isaac. Stops firing when room is cleared.
Constant Stone Shooter	202.0	Stationary and invulnerable monster that continuously fires shots in a single direction.
Gaping Maw	235.0	Stationary and invulnerable monster that sucks Isaac towards it, along with Isaac's tears and enemy projectiles.
Wall Hugger	218.0	Moves around the room like Guts, damaging Isaac by contact. Cannot be destroyed.
Corn	217.1	Quickly dashes in random directions, dealing contact damage.
Dank Squirt	220.1	Dashes towards Isaac and deals contact damage, creating slowing black creep. Spawns 2 Clots upon death.
Dart Fly	256.0	Flies towards Isaac and attempts to predict his movements. Deals contact damage.
Conjoined Fatty	257.0	Slowly walks towards Isaac. Occasionally pauses to fart out a line of damaging Green Creep towards Isaac. Chance to turn into a regular Fatty upon death.
Fat Bat	258.0	Slowly flies towards Isaac. Tries to align itself diagonally to Isaac and shoots at him when in that alignment.
Roundy	276.0	Pops out of the ground in random locations, creating a small rock wave. Fires an explosive Ipecac shot at Isaac if he is in sight.
Swarm	281.0	Follows Isaac in large, tightly-clustered groups and deals contact damage.
Dukie	288.0	Flies around the room diagonally, occasionally spitting out 1-2 Dart Flies.
Ulcer	289.0	Pops out of the ground in random locations and spawns a Dart Fly if Isaac is in sight. Fires a blood shot after spawning 6 Dart Flies.
Corn Mine	295.0	Goes off when destroyed or after some time, then releases a cloud of poisonous gas and fires corny shots in eight directions.
Blue Gaper	297.0	Walks towards Isaac, dealing contact damage.
Blue Boil	298.0	Stationary enemy that decreases in size when hit, but regenerates to its full size until fully destroyed. Fires 1-3 blood shots towards Isaac when fully swollen.
Greed Gaper	299.0	Walks towards Isaac, dealing contact damage.
Mushroom	300.0	Stationary enemy that occasionally pops up and fires four shots in the cardinal or diagonal directions. Takes less damage while its head is down.
Stoney	302.0	Chases Isaac and blocks tears, but does not deal contact damage. Temporarily pauses in exhaustion after a certain amount of time. Invulnerable; dies when the room is cleared.
Blister	303.0	Slowly hops towards Isaac, occasionally spawning a Dark Ball. Spawns a Sack upon death.
The Thing	304.0	Crawls along a wall and attempts to line up with Isaac, then spits a line of damaging Red Creep.
Ministro	305.0	Hops around randomly and hop towards Isaac when he gets close, occasionally spitting out a cluster of disorganized shots.
Portal	306.0	Spawns various enemies from the current floor until it either vanishes or is killed.
Eggy	29.2	Hops aimlessly around the room, spawning slowing white creep wherever it hops. Spawns a group of Swarm Spiders upon death.
Bulb	61.5	Flies in erratic, angled movements toward Isaac if his active item has charges; on contact, they drain up to 2 charges, but never deal contact damage. If he has no active item, or no charges, they wander around the room aimlessly.
Migraine	869.0	Crawls around the room erratically, following Isaac and dealing contact damage. Can jump small distances. Releases multiple Troll Bombs upon death.
Swarm Spider	884.0	Very erratically hops toward Isaac in large groups, dealing contact damage.

Degraded Bosses:

Name	ID	Notes
Blastocyst	74.0	Small-form only
The Hollow	19.1
Larry Jr.	19.0
Teratoma	71.1	Small- and Medium-form only

Bosses[]


Carrion Queen	Dark One	Gurdy Jr.	The Hollow


The Husk	Peep	Polycephalus	The Wretched


Pestilence	The Fallen	Headless Horseman	The Forsaken


The Frail	The Stain	Big Horn	Rag Mega

Bumbino

Double Trouble[]

Double Trouble Bosses


(Double Trouble) Dingle	(Double Trouble) The Duke of Flies	(Double Trouble) Gemini	(Double Trouble) Larry Jr.

File:Boss Monstro.png
(Double Trouble) Monstro	(Double Trouble) Pin	(Double Trouble) Rag Man	(Double Trouble) Gurglings

Trivia[]

In the original Binding of Isaac, Blighted Ovum could appear as a boss.

Unlockable Achievements[]

Something Cute - Beat Chapter 2 30 times.

Telekinesis - Beat Chapter 2 without taking damage.

Spelunker Boy - Beat Chapter 2 without taking damage.

Music[]

The music for the Catacombs is titled Capiticus Calvaria.^[1]
- Calvaria is Latin for "Skull", and while Capiticus does not have a true definition, it's most likely an onomatopoeic expression, or comes from the word Caput, meaning "Head", or Capitulum, meaning "Chapter".