In the game Rain World, Iterators are sapient artificial intelligences running on supercomputers of colossal scale (large enough to build cities on top of). Practically always an Iterator is depicted through its "puppet": a Humanoid Robot which serves as an interface device. Each Iterator's puppet has a characteristic design which includes skin color, a unique Forehead Mark. and various styles of Robot Ears.
Two Iterators can be met in the course of regular gameplay:
An additional three Iterators cannot be met, but have a canonical appearance and play a major role in the events and lore of the game.