|This big slug likes to crush his foes. He spits some mean thread, too!|
— Patch Plaza
Sulkworm is a large caterpillar-like enemy which debuted in Kirby's Epic Yarn and later appeared in Kirby's Extra Epic Yarn. It is fairly uncommon, doesn't move around, and cannot be harmed directly using the Yarn Whip, instead requiring two objects to be thrown at it to defeat. Sulkworm has two methods of attack, both of which can harm Kirby or Prince Fluff. The first is a silk ball which it spits out in an arc, which can be caught and used against it. The second is a body slam attack which it uses at close range. If Kirby is hit, several of his beads may become trapped inside Sulkworm's body, and be unobtainable until the beast is defeated.
- Sulkworm's name is a portmanteau of the words 'sulk' and 'silkworm'.