Mother Brain

Mother Brain is a large, biological computer resembling a cycloptic, spiked brain. Mother Brain is also an enemy of Samus Aran from the Metroid series of games.

Mother Brain's first mention in the Mario series was in the Nintendo Comics System issue "Duh Stoopid Bomb!", where her name (abreviated to M. Brain) can be seen on Wooster's list of people who think King Toadstool is dumb.

Mother Brain is also briefly mentioned by Samus in Super Mario RPG: Legend of the Seven Stars, who claims to be "resting up for Mother Brain".

In WarioWare, Inc.: Minigame Mania one of 9-Volt's microgames has the player, as Samus, battling Mother Brain in a reenactment of the final battle in Metroid. Players must blast Mother Brain repeatedly with missiles and dodge her own attacks in order to defeat her.