The Nightcrawler (also known as "Cyclops Worm") is a monster in The Binding of Isaac: Rebirth (TBOIR)
It has one eye
It acts similar to Round Worms in that it shoots at Isaac then burrows under the ground, only to re-surface in a different location in the room
Nightcrawlers have 4 shots that fly at Isaac at a spiraling path.
Nightcrawers also shoot faster and have more health then the Round Worms