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

Monsters	Description
Sack	Stationary enemy that decreases in size when hit, but regenerates to its full size until fully destroyed. Occasionally spawns Spiders when fully swollen.
Walking Sack	Does not shrink or regenerate. Walks around aimlessly and occasionally spawns Spiders.
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.
Dip	Slowly dashes in random directions, dealing contact damage.
Squirt	Dashes towards the player and deals contact damage. Spawns 2 Dips upon death.
Embryo	Aimlessly hops around the room, dealing contact damage.
Fatty	Slowly walks towards Isaac. Occasionally farts, which pushes Isaac and adjacent enemies away.
Black Fly	Tiny black fly with neutral AI. Does not hurt Isaac upon touch.
Ring Fly	Gathers with any other Ring Flies in the room. These flies orbit around themselves, while following Isaac.
Moter	Follows Isaac, similar to Attack Flies. Splits into 2 Attack Flies upon death.
Pooter	Slow-moving fly that occasionally fires single blood shots at Isaac. Does not deal touch damage.
Level 2 Fly	Flies toward Isaac erratically, dealing touch damage.
Full Fly	Flies toward Isaac erratically, dealing touch damage. Splits into 6 directional shots upon death.
Spit	Flies slowly towards Isaac, firing an Ipecac shot towards Isaac upon death.
Gaper	Walks towards Isaac, dealing contact damage. Usually turns into a Pacer or a Gusher upon death.
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.
Skinny	Slowly walks towards Isaac, leaving short-lasting red creep behind itself.
Horf	Stationary enemy that fires a medium ranged blood shot at Isaac when he gets in range of them.
Psychic Horf	Stationary enemy that fires a homing shot at Isaac when he gets in range of them.
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.
Nest	Walks around the room, avoiding Isaac while spawning Spiders. Spawns a Big Spider or a Trite upon death.
Pacer	Walks aimlessly around the room.
Gusher	Walks aimlessly around the room, occasionally firing short-ranged blood shots.
Round Worm	Pops out of the ground in random locations and spits a blood shot at Isaac if he is in sight.
Nightcrawler	Pops out of the ground in random locations and fires four short-range shots that spiral outwards if Isaac is in sight.
Spider	Erratically moves towards Isaac and deals touch damage.
Big Spider	Erratically moves towards Isaac and deals touch damage. Splits into two Spiders upon death.
Level 2 Spider	Crawls around the room erratically, following Isaac and dealing touch damage. Can jump small distances.
Ticking Spider	Crawls around the room erratically, following Isaac and dealing touch damage. Can jump small distances. Explodes upon death.
Trite	Quickly leaps towards Isaac and deals touch damage.
Ragling	Quickly leaps towards Isaac and deals touch damage. Randomly shoots two purple shots that orbit around it.
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.
Wall Creep	Crawls along walls to try to line up with Isaac and shoots three blood shots in a line.
Poky	Slides around the room aimlessly, damaging Isaac by contact. Disappears when the room is cleared.

Bosses

The Haunt	Blighted Ovum	Pin	Widow

The Duke of Flies	Famine	Fistula	Rag Man	Little Horn

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 Music