Rotten Baby
ItemRebirthUnlocked
familiarGame ID 268★★★★
How do you unlock Rotten Baby?
Verified starting unlockSource data confirms that no unlock is required.
Spawns a familiar that spawns a Blue Fly when Isaac shoots. It can only have one Fly at a time.
Available from the start
No unlock needed — this is available in every new save file.
What unlocking Rotten Baby leads to
Nothing depends on this yet.
Source: bindingofisaacrebirth.wiki.gg
Imported 2026-09-13