The Binding of Isaac: Rebirth.
- If Isaac has half a red heart or no red hearts after taking damage, it grants a black heart.
- The effect can trigger up to three times, after which the trinket will disappear.
- The fingers stuck out by the paw will change to display the number of triggers left.
- The effect can trigger more than once in the same room.
- This trinket will only work with ??? if Isaac have half of an eternal heart, or take damage down to half of a soul heart.
- The Lost will still die when carrying the trinket with a Black Heart spawning afterwards.
- This item is a reference to the supernatural short story The Monkey's Paw by W.W Jacobs.