Worms
Worms are enemies that are characterized by traveling to random points in the room by burrowing in the ground, and often have periodic attacks.
This page is about Worms added by Fiend Folio. More information about Worms in general can be found in the vanilla page.
Drink Worm
Drink Worms will spawn a single projectile which hovers in the air above themselves when they burrow into the ground. They will then emerge from another point in the room that has line of sight with the projectile, and after a delay, they will suck in the projectile from previous position towards their current one. After catching their projectile, Drink Worms will suspend it in the air once more and repeat the pattern.
If the projectile is destroyed, it will spit out a new one when it burrows to replace it.
Bunker Worm
Bunker Worms are large worms with a second smaller head. The large head fires out a large projectile a short distance towards Isaac that comes to a stop midair before burrowing to another location. After burrowing back up, the smaller head will lob a small projectile at the original one that pops it into a ring of 8 projectiles, followed by the big head immediately spitting out another large projectile.
If the large projectile is destroyed, the bigger head will spit out a new one to replace it.
Drunk Worm
Drunk Worms are larger variants of Drink Worms. They spit out 3 big projectiles in the directions of her 3 eyes that bounce off of walls and obstacles before coming to a stop mid-air. They then travel to another point in the room to rhythmically suck in their own projectiles in small bursts. After catching all the projectiles in the room they will spit them out again, continuing the cycle.
Projectiles may get stuck on obstacles while being drawn in, a Drunk Worm will stop attempting to retrieve any stuck projectiles after 5 breaths and replace them. It will also spit out more to replace any destroyed projectiles.
Bone Worm
Bone Worms are a skeletal Round Worm variant that behave similarly, and attack by shooting 4 bone projectiles in the cardinal directions, followed by 4 more in the ordinal directions.
Grater
Graters will always spawn in rooms with 
Grates in the floor. A Grate will shake to indicate that a Grater is about to pop up from beneath it. Upon emerging it will fire a large arcing projectile towards Isaac that creates a pool of black creep where it lands.
After attacking 3 times, all Graters in the room will perform a coordinated attack, telegraphed by all grates in the room shaking at once, which is then followed by fountains of projectiles spewing from from all grates in the room simultaneously for a few seconds.
Trivia
- Drink Worms and Bone Worms each have unique appearances when encountered on the Glacier and Tomb floors respectively if the Revelations MOD is installed.
Gallery
A Drink Worm sucking in its projectile.
Drink Worm's appearance in Downpour.
Drink Worm's appearance in Flooded Caves.
A Bunker Worm with only its small head visible.
A Drunk Worm sucking in its projectiles.
Drunk Worm's appearance in Flooded Caves.
Bone Worm's appearance in Ashpit.
Grates used by Graters to attack and travel around the room.
Drink Worm's appearance in Glacier.
Bone Worm's appearance in Tomb.
Drunk Worm's unused appearance in Womb.
Old version of Grater.
Bunker Worm's original concept art.
Concept art for Bone Worm.
