Boil
Boils start as small red spheres that slowly grow to full size. When at their full size, they can spurt out a cluster of blood shots at Isaac, similar to one of Monstro's attacks. Boils decrease in size when hit, but will regenerate to their full size until fully destroyed.
Boils are nearly harmless on their own, as they can simply be killed from a distance and do not deal touch damage. With other enemies, however, they are far more dangerous: If entering a room with a large crowd of enemies and several Boils providing covering fire, taking out enough of the Boils to give yourself breathing room should be a big priority, especially when fighting Gurdy.
Contents
Variants[edit | edit source]
Gut[edit | edit source]
Guts can replace Boils or Sacks. Instead of firing disorganized blood shots, Guts fire Ipecac shots at Isaac that do not damage them.
They can easily be a nuisance if other enemies are backing them. However, they are rather easy to manipulate into destroying rocks or finding Secret Rooms without using a bomb.
Sack[edit | edit source]
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This article is about the enemy. For the pickup, see Sacks. |
Sacks don't shoot projectiles; instead, they periodically spawn a Spider when fully swollen. Therefore, damaging them will prevent them from spawning Spiders, making them easy to kill. They can commonly be found on the early floors.
Blue Boil[edit | edit source]

Blue Boils are mainly spawned during the Hush fight. Instead of spraying clusters of blood shots, they fire either one blood shot, or three blood shots in a spread towards Isaac. They also regain their health 10x faster than regular Boils if they are damaged but not killed.
They can also rarely appear in
The Depths,
Necropolis or the
Dank Depths.
Notes[edit | edit source]
- Blue Boils that appear in regular rooms can be Champions.
Gush[edit | edit source]

Gushes are enemies similar in appearance to Black Boils. They are stationary, being unable to do any form of damage. Instead, they continuously create slowing Black Creep around them. Unlike other Boil variants, they do not shrink or regenerate.
Although the Black Creep is relatively harmless on its own, Tar Boys can use their special attack if Isaac is standing on the creep.
Trivia[edit | edit source]
- Gushes have been added in Booster Pack #4, after the initial release of the DLC.
Pustule[edit | edit source]

Pustules are stationary enemies that appear to grow out of the ground. They can spawn Small Maggots, and if they are destroyed when fully swollen, they will spawn a Bloodfly.
Trivia[edit | edit source]
- A pustule is the scientific name for a pimple.
Walking Boil[edit | edit source]
Walking Boils act like Boils but randomly wander around the room, can deal half a heart of contact damage and don't shrink or regenerate.
Walking Gut[edit | edit source]
Walking Guts act like Guts but randomly wander around the room, can deal half a heart of contact damage and don't shrink and regenerate.
Walking Sack[edit | edit source]
Walking Sacks act like Sacks but randomly wander around the room, can deal half a heart of contact damage and don't shrink or regenerate.
Notes[edit | edit source]
While regular Boils can be touched without taking damage, champion forms do inflict one heart of damage on touch (like all champions).
- Champion Boils grow significantly slower but take more hits to deflate. The exception to this is gray champions, which grow faster and take fewer hits to deflate.
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