Gutbuster
Gutbusters are variants of 
Crazy Long Legs covered by a skeletal covering, making them invulnerable. After chasing for awhile or once it gets close to Isaac, it will pause and will spit out an Offal, which spawns at random location in the room. With its Offal outside, it will stay stationary and occasionally fire 3 bone projectiles in a row towards Isaac when he draws close. Once its Offal reaches the Gutbuster, it will suck it back up and continue chasing. When its Offal is killed, if there is another Offal in the room, it will move towards the Gutbuster to replace it. Once all Offals in a room are killed, the Gutbuster will die as well.
If hit by an explosion while chasing, a Gutbuster will be stunned for a moment.
Gutbusters can spawn stationary without containing any Offals initially, but will always spawn alongside other Offals in the room.
Notes
- Empty Gutbusters can also spawn alongside the Waiting variant of Offals, wherein they will remain stationary and fire projectiles even while there are no Offals currently active on screen. Once the Offals spawn, Gutbusters can resume their regular behavior.
Offal
Offals are small piles of organs that move in small, jerky movements in random directions.
Offals that are spawned by Gutbusters will slowly inch their way back to their Gutbuster and get sucked up. The Offal will retain its HP when summoned again.
Krass Blaster
Krass Blasters are a variant of of Gutbusters that can be found in Ashpit that behave identically, but chase Isaac extremely slowly. They spawn containing 2 Dried Offals instead of 1 and will fire a spread of 3 bone projectiles towards Isaac while their Dried Offal(s) are ejected. They require both Dried Offals to be killed in order to be defeated.
While empty, they will wait to suck up both Dried Offals they spawned with before chasing again. However, if one is killed, they will resume chasing after sucking up its 1 remaining Dried Offal. With only one Dried Offal, it skitters a bit faster, but still slower than Gutbusters.
Like their counterpart, Krass Blasters can spawn stationary without any Dried Offals, and can occasionally be encountered with only 1.
Dried Offal
Dried Offals behave identically to their regular counterpart, but will periodically pause to fire 4 tiny projectiles in the ordinal directions.
Gallery
An empty Gutbuster.
A Gutbuster stunned after being bombed.
An empty Krass Blaster.
A Krass Blaster stunned after being bombed.
