- Additionally in the Flooded 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:
Champion Versions 
- 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.
- 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.
Mega Fatty as one of Delirium's forms.
An unused sprite for Mega Fatty found among the Room Editor icons.
- 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.
|The Binding of Isaac: Rebirth|
|Achievements||Attributes||Bosses||Cards and Runes||Challenges||Chapters|