SPOILERS FOR RAIN WORLD

An iterator found in Rain World, and "little brother" to Looks to the Moon. A vast bio-mechanical supercomputer situated at the highest point in the game, his machinations are the cause of the titular rain the players endure on the surface world.

When performing a sensitive experiment in an attempt to solve the great problem (see the iterator page for more info), he unintentionally starved Moon of her water. In an attempt to save her own life, she interrupted him, causing his experiment to go awry and creating the rot.