Bound Baby
AchievementAfterbirth+Unlock unknown
Achievement details
- Achievement number
- 403
- Description
- Unlocked a new co-player baby.
- Requirement
- Defeat Mega Satan as The Forgotten
How do you unlock Bound Baby?
In The Binding of Isaac, Bound Baby is unlocked by earning the Mega Satan completion mark as The Forgotten (Character).
Structured pathSource-backed requirements are mapped into trackable steps.
Unlocked a new co-player baby.
- ??? or The Lamb must be defeated once for the Golden Gate to spawn. source
- Open the Golden Gate by combining Key Piece 1 and Key Piece 2 into the Golden Key, or by using Dad's Key or another gate-opening effect. source
- Reach the starting room of Chest or Dark Room, pass through the Golden Gate, and defeat Mega Satan. source
How to unlock: It's complicated
What unlocking Bound Baby leads to
Source: bindingofisaacrebirth.wiki.gg
Imported 2026-09-13