Dark Bum is a passive item.
- Spawns a familiar that follows Isaac around and collects red hearts. For every one-and-a-half red hearts collected, Dark Bum will generate one of the following:
- If Dark Bum enters a Super Secret Room that mimics The Womb, The Cathedral, or The Dark Room / Library, he will drop red hearts, eternal hearts, or black hearts respectively instead of soul hearts.
- If the Super Secret Room mimics The Womb, he will drop red hearts instead of soul hearts, then gobble them back up. This can be avoided by allowing Dark Bum to pick up all of the red hearts and then quickly exiting the super secret room before he starts dropping hearts. This way, he will drop a considerable amount of soul hearts.
- Dark Bum will not pick up Gold Hearts, Blended Hearts, or Bone Hearts.
- ???: Greatly improves chances of survival, due to Dark Bum converting useless red hearts into useful soul hearts.
- BFFS!Increases the size and damage of familiars.: Familiar is bigger and increased chance of dropping pickups. 
- Little C.H.A.D.A familiar who will drop a half red heart every 2 rooms.: Convert hearts dropped by Little C.H.A.D. into soul hearts.
- GimpyHas a chance of spawning a soul heart or black heart when taking damage. Enemies have a chance to drop a Half Red Heart after being killed.: When enemies die and drop red hearts, they get converted into soul hearts.
- Humbling BundleGives one extra pickup (1+1 Free version) of Red Hearts, pennies, bombs, and keys. Does not work with blue, black, and half red hearts, nickels, and dimes.: All red hearts dropped are double hearts, so the conversion ratio is greatly improved.
- Child's HeartIncreases the chance of a Heart dropping after clearing a room, and the chance of finding a Heart when opening a Chest.: Increases red heart drops and thus increases usage of Dark Bum.
- The Forgotten: Makes it harder to keep The Forgotten's bone heart containers, since every red heart on the floor will be collected and transformed into soul hearts, which can only be used by The Soul.
- Keeper: Heart pickups cannot spawn, rendering Dark Bum useless.
- v1.02: Dark Bum's red to soul heart conversion rate was set to 1.5:1.
- v1.031: Dark Bum was changed to have a chance to spawn friendly or hostile spiders.
WBEG Q22R (treasure room adjacent to spawn)
CS9M XL2P (treasure room adjacent to spawn)
AL07 13JY (treasure room adjacent to spawn)
7276 4P61 (treasure room adjacent to spawn)
EVQ8 P80Q (treasure room adjacent to spawn)
|The Binding of Isaac: Rebirth|
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