- For other uses, see Worm (disambiguation).
The Round Worm is a worm-like monster added in The Binding of Isaac: Rebirth.
Round Worms behave similar to Para-Bites and Horfs. When Isaac is within range of one, it shoots 1 bullet at him. Afterwards, it teleport by burrowing off to somewhere else in the room. When Isaac is out of range, it doesn't shoot and burrows somewhere else.
- 1 Round Worm can be spawned by Polycephalus at a time.
- Sometimes, a single Round Worm will appear during the boss battle against Pin.
- They are named after in real-life parasites which were also known as "nematodes".