|Floors of Appearance||All Floors|
|Base Health||20 (When Full)|
|Deals Contact Damage||No|
|Type of Tears||Barrage|
The Boil is an enemy in The Binding of Isaac: Rebirth that is commonly found on all floors. It is a large, swelling boil.
- The Boil is immobile. It starts off very small, but quickly grows. Its size represents both its health and how close it is to firing. When the Boil is fully grown, it will occasionally fire a barrage of tears in a random direction. The Boil constantly grows until it is either its full size or killed. When damaged, it shrinks in size. The Boil is spawned by Gurdy and other bosses.
- The player should kill Boils as soon as possible as they are weakest when the room is first entered. However, if multiple Boils should happen to grow to their full size, the player should balance the sizes, not allowing any Boils to shoot.
- Only Champion version of Boils deal contact damage.