Dead Cat 
Effects
- Sets Isaac's Red Heart containers to 1.
- Grants 9 extra lives.
- Upon death:
- Isaac respawns in the previous room with 1 Red Heart container.
- Any active items in Isaac's possession will lose all its charges.
- The head of Guppy begins following Isaac like a familiar upon pickup but doesn't do anything.
- When Isaac has lost all of the lives provided by this item, the Guppy familiar will disappear.
- This item belongs to the Guppy set. Collecting three items from this set will transform Isaac into Guppy.
Notes
- This item can drop from Super Pride.
- Resurrection items activate in a set order. Dead Cat is (Removed in Repentance) 3rd / (Added in Repentance) 4th in this order after (Added in Repentance)(Soul of Lazarus) Soul of Lazarus,
1up!, and (Lazarus) Lazarus' extra life.
- (Removed in Afterbirth) Picking this up as (The Lost) The Lost would not show the number of remaining lives, but will still function.
- (Added in Afterbirth †) If picked up as (The Forgotten) The Forgotten, his Bone Hearts are reduced to 1 but
The Soul's Soul Hearts remain unaffected. The reverse is also true.
- The lives are added after the "picking up an item" animation has ended, so characters that die while the animation is playing will not be revived by this item.
- (Removed in Repentance) The effects of the
D4, 
D100, 
Missing No., or a 1- or 6-pip (Dice Room) Dice Room will not remove the lives granted by this item.
- Additional Dead Cats can be picked up during a run, increasing lives well past 9. (Removed in Repentance) Only the first dead cat counts toward becoming Guppy.
- (Added in Afterbirth † / Removed in Repentance) This item counts as 9 items, so if Isaac is trying for an early portal to after beating Mom, this will significantly boost the progress closer to 20 items.
- (Added in Repentance) If (Jacob and Esau) Jacob and Esau take the item, only the brother who takes it will be set to one Red Heart Container on pickup. But if they die, both are resurrected with one Red Heart Container.
- (Added in Repentance) If (Tainted Jacob) Tainted Jacob takes this item after being touched by Dark Esau, he will return to his previous Red Heart total upon reaching the next floor.
- Dying as Tainted Jacob after being touched by Dark Esau and carrying this item will respawn him in the previous room in his lost form. Making it to the next floor will still return him to his previous Red Heart total.
Synergies
- (Added in Afterbirth)
Diplopia: Isaac gains 18 extra lives in total.
- Gold Hearts: Gives Isaac many coins when picked up, due to the amount of hearts lost.