Key Bum

"He wants your keys!"
Entity ID	5.100.388
Item Pool	Baby Shop Key Master Secret Room Treasure Room
Collection Grid	(page 4, column 3, row 2) (page 4, column 3, row 2) (page 4, column 4, row 2)
Unlock Method	Defeat Ultra Greed as Lazarus

Key Bum is an unlockable passive item added in Afterbirth.

Effects

• Spawns a familiar that follows Isaac around and collects keys, dropping random Chests in return. (He does not fill up a familiar "slot".)
• This item belongs to the Super Bum set. Collecting three items from this set will transform Isaac's bums into Super Bum.

Notes

• Key Bum will not pick up golden keys.
• Key Bum will pick up charged keys without additional benefit.
• Key Bum will leave a Lil' Battery behind when picking up charged keys.

Synergies

• BFFS!: Familiar is bigger and drops chests more often.
• The Left Hand/ Gilded Key: Works as expected.
• Flat Penny: Chests frequently contains pennies, which have a chance of spawning more keys for Key Bum to pick up, possibly lead to a loop.
• Guppy's Eye: Allows Isaac to choose which Locked Chests are worth opening and which to pass, thus saving keys. Great for min-maxing.

Seeds

PC WJK1 9R0Z (Treasure Room adjacent to spawn)

Bugs

Bug!	If Credit Card is used in a Shop with keys, Key Bum will not be able to pick up the free keys. This can be fixed if Isaac leaves and re-enters the shop.

Bug!	Charged Keys do not increment Key Bum's key count when picked up.