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

Mega Fatty is a boss that can appear in Caves Caves.


  • Leaps off-screen and tries to land on Isaac's position, leaving a large puddle of Red Creep upon landing.
  • Slides briefly towards Isaac and performs a short-range jump, also leaving Red Creep when he lands.
  • Inhales, drawing in Isaac and any monsters towards him, before then vomiting upwards, unleashing a barrage of projectiles into the air. The projectiles will rain down for a short duration, following Isaac's movements.
  • Farts, which can damage Isaac if he's too close, and will either:
    • Summon 1-3 Dips.
    • Unleash a cluster of projectiles behind him, similar to Monstro.

Champion Versions Needs to be unlocked[]

  • Added in Afterbirth Brown: Has 15% more HP (690). He will not use his vomit attack and sends out rock waves instead of leaving Red Creep upon landing when performing the long-range jump, similar to The Cage.
  • Added in Afterbirth Red: 33% smaller and has 10% less HP (540). Shoots 6 bullets instead of leaving Red Creep upon landing. Creates Red Poop instead of Dips. Vomit attack sends out four projectiles stream attacks in a pattern similar to Mom's Heart/It Lives. Due to the high tear height of the vomit attack projectiles, it is nearly impossible to get hit by them.



  • 15►Lost Contact Lost Contact will still block all incoming projectiles from his barrage even if they happen to go high enough to be offscreen.


  • He is the boss version of the Fatties.
  • The Cage is the posthumous version of Mega Fatty.
  • The picture of Mega Fatty on Isaac's last will closely resembles the unused variant.

Bosses Boss Monstro.png
Chapter 1
Stage Basement icon.pngStage Cellar icon.pngStage Burning Basement icon.png
GeminiStevenBlighted OvumDingleThe Duke of FliesFamineGurglingsThe HauntLarry Jr.MonstroPinWidowThe FallenThe Headless Horseman
DangleLittle HornRag ManTurdlings
Baby Plum
Chapter 1.5
Stage Downpour icon.pngStage Dross icon.png
Lil BlubWormwoodThe RainmakerMin-MinClogColostomiaTurdlet
Chapter 2
Stage Caves icon.pngStage Catacombs icon.pngStage Flooded Caves icon.png
FistulaChubC.H.A.D.Carrion QueenDark OneGurdyGurdy Jr.The HollowThe HuskMega FattyMega MawPeepPestilencePolycephalusThe WretchedThe FallenThe Headless Horseman
The ForsakenThe FrailThe Stain
Big HornRag Mega
Chapter 2.5
Stage Mines icon.pngStage Ashpit icon.png
Reap CreepTuff TwinsHornfelGreat GideonSingeThe ShellThe Pile
Chapter 3
Stage Depths icon.pngStage Necropolis icon.pngStage Dank Depths icon.png
The AdversaryThe BloatThe CageThe GateMonstro IIGishLokiMask of InfamyWarThe FallenThe Headless HorsemanMom
Sisters Vis
Reap CreepThe Pile
Chapter 3.5
Stage Mausoleum icon.pngStage Gehenna icon.png
The SirenThe HereticThe VisageThe Horny BoysMomMom's Heart
Chapter 4
Stage Womb icon.pngStage Utero icon.pngStage Scarred Womb icon.png
BlastocystThe BloatConquestDaddy Long LegsTriachnidDeathLokiiMama GurdyMr. FredScolexTeratomaThe FallenThe Headless HorsemanMom's HeartIt Lives
Sisters VisThe Matriarch
Stage Corpse icon.png
ChimeraThe ScourgeRotgutMother
Chapter 5
Stage Sheol icon.pngStage Cathedral icon.png
Chapter 6
Stage Dark Room icon.pngStage Chest icon.png
???The LambMega Satan
The Void
Stage The Void icon.png
Stage Home icon.png
DogmaThe BeastUltra DeathUltra FamineUltra PestilenceUltra War
Greed Mode
Ultra Greed
Ultra Greed
Ultra Greedier
The Binding of Isaac: Rebirth The Binding of Isaac: Rebirth The Binding of Isaac: Rebirth
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Characters Characters MainPageBabies.png Co-op Items Items Item pools Item pools Monsters Monsters Objects Objects
Pickups Pickups Pills Pills Rooms Rooms Seeds Seeds Transformations Transformations Trinkets Trinkets