Conjoined Fatty is a double-headed type of regular Fatties added to the Afterbirth expansion for The Binding of Isaac: Rebirth. They appear in The Basement of Chapter 1 very rarely and commonly found in Chapter 2.
Conjoined Fatties behave identically to normal Fatties but with different sounds. They have an ability to spit a line of harmful green creep. However, unlike the normal Fatty, they can't perform a fart ability.
They will have a chance to turn into a regular Fatty upon death.
- If killed while spitting creep, the creep line won't grow to its full length. It will instead stop spreading as soon as the Conjoined Fatty gets killed.