The Cellar

(chapter 1)

2

1a, 2a

Beat all The Basement bosses (not restricted to beating bosses in the Basement)The Cellar

The Cellar is one of the environments in chapter 1. It is unlocked after defeating each boss in The Basement, including defeating the smallest twin first in Gemini's fight. It is not necessary to defeat Steven to unlock the Cellar. The theme of the Cellar is spiders and poop.

Monsters

Monster	Description
Frowning Gaper	Walks towards Isaac, dealing contact damage. Upon getting near Isaac, it will open its eyes and pursue Isaac faster. Usually turns into a Pacer or a Gusher upon death.
Gaper	Walks towards Isaac, dealing contact damage. Usually turns into a Pacer or a Gusher upon death.
Gusher	Walks aimlessly around the room, occasionally firing short-ranged blood shots.
Pacer	Walks aimlessly around the room.
Horf	Stationary enemy that fires a medium ranged blood shot at Isaac when he gets in range of them.
Pooter	Slow-moving fly that occasionally fires single blood shots at Isaac. Does not deal touch damage.
Super Pooter	An alternate version of the Pooter that fires 2 shots in a V-formation and does not deal touch damage.
Clotty	Randomly wanders around the room, firing 4 blood shots in the cardinal directions.
Clot	Randomly wanders around the room, firing 4 tar shots in the ordinal directions.
I.Blob	Randomly wanders around the room, firing 8 shots in all directions.
Mulligan	Walks around the room, avoiding Isaac. Upon death, spawns several flies, which can be Black Flies, Attack Flies, or Pooters. Can suicide to explode and launch projectiles in the four ordinal directions while still releasing flies.
Mulligoon	Walks around the room, avoiding Isaac. Upon death, spawns a Troll Bomb and fires four shots in the ordinal directions. Can suicide to explode, spawn a Troll bomb, and launch projectiles in eight directions.
Mulliboom	Chases Isaac and explodes upon death or upon touching Isaac. The explosion deals a half-heart of damage instead of the regular full heart.
Attack Fly	Red fly that follows Isaac and deals touch damage.
Trite	Quickly leaps towards Isaac and deals touch damage.
Sack	Stationary enemy that decreases in size when hit, but regenerates to its full size until fully destroyed. Occasionally spawns Spiders when fully swollen.
Slide	Quickly slides towards Isaac when he gets in its line of sight, then moves slowly back to its original position. Cannot be destroyed.
Sucker	Flies slowly towards Isaac, exploding into 4 shots in the cardinal directions upon death.
Spit	Flies slowly towards Isaac, firing an Ipecac shot towards Isaac upon death.
Embryo	Aimlessly hops around the room, dealing contact damage.
Moter	Follows Isaac, similar to Attack Flies. Splits into 2 Attack Flies upon death.
Spider	Erratically moves towards Isaac and deals touch damage.
Walking Sack	Does not shrink or regenerate. Walks around aimlessly and occasionally spawns Spiders.
Big Spider	Erratically moves towards Isaac and deals touch damage. Splits into two Spiders upon death.
Nest	Walks around the room, avoiding Isaac while spawning Spiders. Spawns a Big Spider or a Trite upon death.
Baby Long Legs	Runs away from Isaac and frequently spawns Spiders.
Small Baby Long Legs	Runs away from Isaac and occasionally spawns Sacks.
Crazy Long Legs	Chases Isaac, dealing touch damage. Occasionally stops to spit blood shots in 8 directions.
Small Crazy Long Legs	Chases Isaac, dealing touch damage. Occasionally stops to spit blood shots diagonally in 4 directions.
Fatty	Slowly walks towards Isaac. Occasionally farts, which pushes Isaac and adjacent enemies away.
Pale Fatty	Slowly walks towards Isaac. Occasionally farts and shoots blood shots in 6 directions. Can turn into a Blubber upon death.
Blubber	Walks around aimlessly and randomly spews blood around itself. Can turn into a Half Sack when killed.
Dip	Slowly dashes in random directions, dealing contact damage.
Brownie Corn	Slowly dashes in random directions, dealing contact damage.
Wall Hugger	Moves around the room like Guts, damaging Isaac by contact. Cannot be destroyed.
Squirt	Dashes towards the player and deals contact damage. Spawns 2 Dips upon death.
Ring Fly	Gathers with any other Ring Flies in the room. These flies orbit around themselves, while following Isaac.
Skinny	Slowly walks towards Isaac, leaving short-lasting red creep behind itself.
Wall Creep	Crawls along walls to try to line up with Isaac and shoots three blood shots in a line.
Round Worm	Pops out of the ground in random locations and spits a blood shot at Isaac if he is in sight.
Ragling	Quickly leaps towards Isaac and deals touch damage. Randomly shoots two purple shots that orbit around it.
Psychic Horf	Stationary enemy that fires a homing shot at Isaac when he gets in range of them.
Full Fly	Flies toward Isaac erratically, dealing touch damage. Splits into 6 directional shots upon death.
Ticking Spider	Crawls around the room erratically, following Isaac and dealing touch damage. Can jump small distances. Explodes upon death.
Dart Fly	Flies towards Isaac and attempts to mimic his movements. Deals contact damage.
Conjoined Fatty	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.
Roundy	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.
Black Globin's Head	Slides towards Isaac, leaving a trail of damaging red creep.
Black Globin's Body	Walks aimlessly around the room, occasionally spawning spiders.
Swarm Fly	Follows Isaac in large groups and deals contact damage.
Mega Clotty	Slowly moves around the room, occasionally hopping and firing 6 blood shots in all directions. Splits into two Clotties upon death.
Cyclopia	Walks towards Isaac, dealing contact damage and leaving behind a trail of damaging red creep. Occasionally shoots a blood shot towards Isaac.
Ulcer	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.
Blue Gaper	Walks towards Isaac, dealing contact damage.
Greed Gaper	Walks towards Isaac, dealing contact damage.
Stoney	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.
Portal	Spawns various enemies from the current floor until it either vanishes or is killed.

Degraded Bosses
Blastocyst (small)

Bosses

Blighted Ovum	The Duke of Flies	Fistula	The Haunt

Pin	Widow	The Fallen	Famine

The Headless Horseman	Little Horn	Rag Man

Notes

• Unlocking the Cellar requires defeating every boss in the Basement. However, this does not require actually fighting them in the Basement. It is possible, for instance, to have defeated every single boss except for the Gurglings, encounter them in the Womb, clear the room in which they are encountered, and successfully unlock the Cellar.

Unlockable Achievements

• 

  Something From The Future - Beat The Basement 40 times.

• 

  Sprinkler - Beat chapter 1 without taking damage.

• 

  Basement Boy - Beat chapter 1 without taking damage.

Music

The music for the cellar is titled Periculum. Periculum is Latin for "danger" or "risk", signifying how the Cellar is a step-up from the Basement.

Binding of Isaac: Rebirth OST