Aliens are extraterrestrial beings of various forms. They do not originate from Earth, but are instead believed by some to have been created by The Goddess of Life on countless different planets throughout the universe. They do, however, depend on the powers of Creation to exist, supporting the idea that they too are byproducts of Creation's eternal sleep.
Many varied species have been shown to exist. Most famously: Homeworldians, Cerebral Cerebellum and the Aliens that attacked Earth during the Virus outbreak (although they later turned out to be ancient slime monsters)