Sets the Devil Room chance to 100% regardless of all other modifiers, guaranteeing a Devil Room or Angel Room Door will spawn whenever possible and remain open.
Notes
Even if taken after a boss is killed, Goat Head will force a Devil / Angel Room door to spawn on that floor.
Taking a deal with the Devil will prevent Angel Rooms from appearing, meaning Goat Head must be acquired from another source for an Angel Room to spawn.
Goat Head will not force a Devil / Angel Room door to open if the boss fight was in a narrow room.
Goat Head has no effect in Greed mode and is not normally available.
By touching the white fire in Downpour II and Dross II, Isaac will temporarily become The Lost. After defeating the boss, Goat Head will always keep the devil deal door open, allowing the Lost to take one Devil Deal item for free.
Devil Room or 
Angel Room Door will spawn whenever possible and remain open.
Goat Head will not force a Devil / Angel Room door to open if the boss fight was in a narrow room.
Goat Head has no effect in Greed mode and is not normally available.
Eden, a bonus item from 
Eden's Blessing, and is obtainable with 
Pandora's Box and 
Sacrificial Altar.
By touching the white fire in 
Downpour II and 
Dross II, Isaac will temporarily become 
The Lost. After defeating the boss, Goat Head will always keep the devil deal door open, allowing the Lost to take one Devil Deal item for free.
Black Feather: Grants a damage boost.
Duality: Both Angel and Devil Room doors spawn after every boss, and the selected door will never disappear.
Eucharist: Overrides Goat Head.
The Binding of Isaac: Rebirth
