Mom's Key is a passive item.
- Gives Isaac two keys.
- If a non-Red Chest spawns hearts, coins, bombs and/or keys, causes the chest to spawn a second group of said pickups, effectively doubling the average pickup yield.
- This item belongs to the Yes Mother? set. Collecting three items from this set will transform Isaac into his mother.
- Mom's Key cannot change the contents of a chest; it will only cause it to spawn extra pickups.
- All other chest rewards (such as pills, cards, items, etc.) will not cause the chest to spawn additional pickups.
- Does not affect Old Chests.
- Mom's Key is the first item, by ID number, that was not carried over from Wrath of the Lamb.
- The appearance of Mom's Key is a reference to Bowser's boss key in Super Mario 64 as well as the Boss Key in various Legend of Zelda games.
- Prior to Repentance, this item's description was "Less is now more +2 keys".