The Carrion Queen is the posthumous version of Chub that appears as a boss in the Catacombs and Necropolis, and as a miniboss in The Chest. She appears as a skeletal worm with a soft, fleshy spot at the very back of her tail.
Carrion Queen's movement pattern and charge attack is identical to Chub's. However, she can only be damaged by firing shots at her uncovered tail (much like Knights) or by being fed Bombs during her charge.
Instead of spawning monsters, she spawns Red Poop. These piles can be collapsed much like regular poop, but will regrow shortly after.
When her health reaches below the halfway point, her attack pattern changes to a mad dash about the room in a zig-zag pattern, similarly to The Hollow. If her tail is shot during this phase, she will immediately change direction as if bouncing off of a wall. She does not charge at Isaac during this phase. If any poop piles linger from the first phase, she can bounce off them to unexpectedly change her path.
- Even after defeating The Carrion Queen, her red Poop will remain and can still harm the player. It is removed when re-entering the room.
- This foe takes reduced damage from explosions. Carrion Queen has only one segment in addition to this, so explosive damage is generally much reduced in value. This is balanced by her lower HP.
- Dropping a bomb in the path she is charging will cause her to eat it, stunning and dealing bonus damage to her.
- She is poison immune. The Virus can still harm her with contact damage.
- Refighting her via use of black fly or dying and rentering the room after defeat, will cause her weak spot to disappear thus being rendering the boss unfinishable. The champion cannot be defeated in any way either because she is unable to spawn mini hearts
She is smaller in size and does not move diagonally during the fight. This version also spawns tiny Hearts (40 HP each), which shoot bullets in a long ranged cross pattern, instead of red poop. Killing a heart will deal 40 damage to Carrion Queen, in addition to her standard weak point. This form is best killed by attacking the hearts.
- She will not spawn tiny hearts if there's more than 2 Carrion Queens in current room.
Eternal Carrion Queen is basically the same as her Pink variant, but spawns Eternal Hearts instead. Shooting at her head also causes the tears to be reflected back.
- According to Edmund McMillen, the Carrion Queen's poop is made out of AIDS.
- Carrion is dead animal matter. So, saying Carrion Queen would be the Queen of the dead carcasses or simply the dead.
- It is possible to make the Carrion Queen immortal with Mom's Contact if only the vulnerable part is frozen while she's currently charging. She will proceed to move and then teleport back afterwards. If this occurs there is no way to kill her in conventionally.