Binding of Isaac: Rebirth Wiki
Binding of Isaac: Rebirth Wiki

Disambig.png This article is about the monster. For the boss, see Mega Fatty.

Fatties walk slowly toward Isaac occasionally stopping to fart, which pushes Isaac away without dealing damage if he is too close. This will also push away adjacent enemies to a lesser degree.


Pale Fatty[]

Pale Fatties behave like Fatties, but will also spit out 6 blood shots in all directions when farting. When killed, they have a chance to become a Blubber or a Half Sack.

Flaming Fatty[]

Added in Afterbirth

Flaming Fatties behave identically to regular Fatties but have a chance to leave behind a damaging flame upon death. Added in Repentance They can also spawn a damaging flame by farting.

Unlike other flaming enemies they are not immune to damage from fire sources and regular Fatties will not turn into Flaming Fatties upon contact with any source of fire.

Fat Sack[]

Fat Sacks walk slowly towards Isaac and can leap offscreen and attempt to land on Isaac, shooting 6 bullets in all directions and leaving a puddle of Red Creep behind when it lands. Like Pale Fatties, they have a chance to turn into a Blubber or Half Sack when killed. These monsters behave very similar to Leapers.


Blubbers walk aimlessly around the room, randomly spewing a cluster of blood shots in all directions. When killed, there is a chance for it to become a Half Sack.

Half Sack[]

Half Sacks walk aimlessly around the room and leave behind a trail of Red Creep.

Conjoined Fatty[]

Added in Afterbirth

Conjoined Fatties slowly walk towards Isaac and occasionally pause to fart out a line of damaging Green Creep. There is a chance that upon death, it will turn into a regular Fatty.

If killed while farting, the Creep line won't grow to its full length. It will instead stop spreading the instant the Conjoined Fatty is killed.

Blue Conjoined Fatty[]

Added in Afterbirth

Blue Conjoined Fatties slowly walk towards Isaac and occasionally fart out a homing Ipecac shot at Isaac. Unlike normal Conjoined Fatties, they won't turn into any kind of Fatty upon death.


  • Removed in Repentance They only appear in normal mode.
    • D10 D10 can be used to reroll non-boss enemies in Chest Chest and in Added in Afterbirth † The Void The Void into Blue Conjoined Fatties even on Hard mode.
  • Added in Repentance They can also appear in ??? ??? with the use of Red Key Red Key or by entering Treasure Rooms with the Blue Key Blue Key.
  • Added in Repentance Blue Conjoined Fatties now have a new appearance, resembling that of Hush.

Peeping Fatty[]

Added in Repentance

Peeping Fatties slowly walk towards Isaac and occasionally fart out 6 blood shots in all directions. They are unique in that they have two indestructible Peeping Fatty Eyes that float around them that are out of socket and attached by muscles.

Each eye generally prioritizes its focus on Isaac, but will occasionally become interested in something else, which could be an enemy, obstacle, or a collectible. The Peeping Fatty will sometimes begin perusing whatever one or both of his eyes have become fascinated with but will also prioritize chasing Isaac if he is in view.

If both eyes are destroyed (using Euthanasia Euthanasia for example), the Fatty will become blind and wander around randomly.


Added in Repentance

Bloaties unlike other fatties, seem to be blind and do not chase Isaac nor target him. They lumber in random directions and periodically spit out a line of Green Creep and arcing projectiles in the direction they are facing or to its either side, horizontally or diagonally. The initial creep shot can hit Isaac even if he has flight. Upon death they leave a small puddle of green creep.


Added in Repentance

Bubbles slowly walk towards Isaac like regular Fatties and will occasionally fart sending out a burst of short range projectiles in all directions. Hitting a Bubbles will cause it to shoot a projectile in a random direction. Upon death, they will burst into a geyser of projectiles that rain down in a large radius.


Added in Repentance

Shadies follow Isaac at a faster pace than regular Fatties and have two attacks which they perform. They can shoot a large black and red projectiles towards Isaac which releases perpendicular shots to itself while traveling. These perpendicular shots accelerate while travelling. Upon colliding with a wall, the large projectile creates a ring of shots. Occasionally, Shadies may jump in place, causing lines of explosions in the cardinal directions upon landing.


Added in Repentance

Quakeys walk slowly towards Isaac and occasionally attempt to jump on Isaac, shooting out 8 rock shots when they hit the ground and causing rocks to fall from the ceiling. Isaac will take knockback if he is standing too close to a Quakey's zone of impact.

Big Bony[]

Added in Repentance

Big Bonies walk towards towards Isaac, and occasionally fire a large bone projectile that bounces off of objects and can be destroyed.

Vis Fatty[]

Added in Repentance

Vis Fatties spawn with a Fetal Demon attached to their slit abdomens. The Fatty will slowly walk towards the player while the Fetal Demon occasionally lunges towards Isaac if he gets too close. As it is tethered, the Demon has a limited range of movement. Occasionally the Vis Fatty will fart, which briefly pushes the Fetal Demon away, giving it a substantial increase in range, as well as creating puddles of damaging Red Creep around the Fatty, the Demon and the cord that attaches them.

If the Fatty is killed first, the Demon will be broken free and continuously chase down the player similar to Gemini's Suture. If the Demon is killed first, the Vis Fatty unleashes a Brimstone Brimstone laser in the closest diagonal direction to Isaac. It will then fly backwards around the room diagonally, bumping off of walls and tall blocks all while continuously shooting Brimstone Brimstone behind it.

Fetal Demon[]

Added in Repentance

Fetal Demons usually spawn tethered to a Vis Fatty's slit abdomen and occasionally makes short lunges towards Isaac if he gets close. They can also be propelled a longer distance when the Vis Fatty farts. If the Vis Fatty is killed they will chase Isaac similarly to Gemini's Suture. The only other place where they can be encountered is in the Mom fight in Mausoleum Mausoleum / Gehenna Gehenna, and is the only place where they are encountered alone.

Gutted Fatty[]

Added in Repentance

Gutted Fatties lumber around the room aimlessly and occasionally shoot out a pile of Festering Guts downwards leaving a trail of Red Creep. They can spawn a maximum of 3.

Every time a third of the Gutted Fatty's health is depleted, it spawns a Gutted Fatty Eye. These eyes normally float around the Gutted Fatty they emerged from and block shots. Whenever Isaac walks too close to one of these eyes they will abandon their position and begin slowly chasing him instead. The eyes will return to defending the Gutted Fatty if Isaac walks far enough away from them. The eyes only die when the Gutted Fatty dies.

Upon death, the Gutted Fatty explodes into a massive shower of blood projectiles, similar to that of Bubbles.

Tainted Faceless[]

Added in Repentance

Tainted Faceless walk towards towards Isaac while releasing 6 blood shots in a hexagonal shape rapidly. They essentially behave like Faceless with higher health and faster attack rate.


Added in Afterbirth †

Stoneys walk towards Isaac while blocking his shots. They stop and catch their breath after chasing Isaac for a few seconds. They do not do contact damage but will often push Isaac around. They are invincible, but die when the room is cleared, similar to the Death's Head enemies. Stoneys are unlocked by defeating The Lamb for the first time.


  • If Stonies aren't unlocked yet, Conjoined Fatties will usually spawn in their rooms instead, although Fatties are also placeholders for Stonies in some rooms.
  • Spectral tears and Removed in Repentance piercing tears will pierce through Stoneys.
  • Removed in Repentance If they are poisoned with The Virus The Virus, upon clearing the room, they have a chance to drop a Black Heart despite not taking damage.
  • Removed in Repentance Touching a Stoney can break open Walnut Walnut.
  • Stoneys are immune to all status effects.
  • Stoneys can be killed with Chaos Card Chaos Card, Euthanasia Euthanasia, and Little Horn Little Horn.
  • Stoneys were nerfed in update v1.06.0188 by making them pause in exhaustion after following the player. Before that, Stonies would continually chase the player.

Cross Stoney[]

Added in Afterbirth †

A Cross Stoney is a type of Stoney added in Booster Pack #5. These new enemies act like a hybridization of a Stoney and a Cross Stone Shooter; they constantly chase the player like a Stoney but will shoot 4 shots outwards vertically and diagonally like a Cross Grimace.

Cross Stoneys only appear in challenge #32 (Aprils Fool) as replacements to regular Stoneys.



  • Blubbers appear to be headless Pale Fatties or, more accurately, headless Fat Sacks.
    • Similarly, Half Sacks appear to be the lower portions of Pale Fatties or, more accurately, the lower portions of Fat Sacks.
  • Conjoined Fatties and Blue Conjoined Fatties suffer the condition of polycephaly, having more than one head.
  • Conjoined Fatties and Blue Conjoined Fatties make the same high-pitched growling noises as Gapers instead of the lower-pitched ones used by other Fatties.
  • Stoneys look very similar to Stone Grimaces with bodies.
  • Stoneys make the sounds of a pitched-down Gaper.
    • Added in Repentance Stoneys make the sounds of a pitched-down Fatty.
  • Cross Stoneys do not appear in regular runs; they only appear in the Aprils Fool challenge.
  • Antibirth developer Kilburn first revealed Cross Stoneys on the 1st of April for Booster Pack #5.[1]
    • It was revealed on the 1st of April, and Cross Stoneys are exclusive to the Aprils Fool Challenge.
  • Added in Repentance Blue Conjoined Fatties were redesigned to look similar to Hush.
  • In Antibirth, Quakies used to have a face of a regular Fatty.
  • In Antibirth, Big Bony's bone attack used to be different - the bone was a lobbed projectile that created shockwaves in the place of its impact. Big Bonies also used to spawn in Mausoleum Mausoleum.
  • Added in Repentance Vis Fatties look very similar to Exorcists.