Aurora Unit

An Aurora Unit is an organic supercomputer used by the Galactic Federation for scientific, government, business, and military purposes. They are first seen in Metroid Prime 3: Corruption.

Appearance
Auroras appear to be giant brain-like objects floating in tubes. They have several wires connecting them to their source.

History
The first Aurora was created 20 years before the events of Metroid Prime 3. They were originally created for scientific research, but have since been built for the government, businesses, and the military. Each Aurora, as a sentient being, is given either a male, female, or gender-neutral persona. Every Aurora is connected in a massive database.

Mother Brain
Samus's primary enemy in the original Metroid games was Mother Brain, a one-eyed brain in a tube. Mother Brain's resemblance to an Aurora is obvious, at the end of the "Aurora" video on the Metroid Prime 3 Preview Channel, a room containing an Aurora is shown. The room resembles exactly the room in which Samus fights Mother Brain in her various appearances.

Mother Brain's origin: the Chozo vs. the Federation
The Metroid e-manga, which is generally regarded as canon, states that Mother Brain was originally created as a computer for the Chozo, and somehow became a brain in a tube before or during her defection to the Space Pirates. This would seem to create an inconsistency with the games, where Mother Brain is clearly meant to either look like or actually be an Aurora Unit. However, in the e-manga, Mother Brain is originally built at a spherical floating computer. It is possible the Federation rebuilt her as a brain and used her design to build other Auroras. The video states that Auroras were first built 20 years ago, which matches up with Samus's age. The Federation could have stolen the Chozo's idea or helped them rebuild Mother Brain.