Mother Brain

Mother Brain is a large, biological computer resembling a cycloptic, spiked brain and the leader of the Space Pirates and a recurring antagonist in the Metroid franchise. Her first appearance in the Super Smash Bros. series is in Super Smash Bros. Brawl, as a sticker.

Mother Brain appears as an Assist Trophy in Super Smash Bros. for Nintendo 3DS / Wii U. When she first appears, several Rinkas appear that damage opponents, though, as they are energy-based, they can be absorbed or reflected. After some time she then uses the Laser Brain Attack for massive damage. When she uses the attack, however, the glass surrounding her container shatters, allowing opponents to attack and defeat her. She returns as an Assist Trophy in Super Smash Bros. Ultimate, having the same behavior, and she also appears as a spirit.

Trivia

 * In the Brinstar stage seen in many Super Smash Bros. games, a massive brain can be seen occupying the background, writhing and occasionally sprouting wound-like growths whenever it comes in contact with the acid. Brinstar Depths contains another brain, this one smaller and trapped within a spherical spiked cage. It is unclear if either of these are intended to represent Mother Brain, though they do not particularly resemble any form of hers from the Metroid franchise.