Mother Brain resembles a human brain, though she is more spherical in shape. She has short metal spikes protruding from the top of her scalp, and a single large eyeball with an iris colored differently in each game she appears in. The brain is also a bright red. Several power cables come off the bottom of her body, and she appears to be permanently attached to the floor of her tank. Her tank, called the Control Capsule in the Super Metroid comic, is protected by Rinkas.
Summons Rinkas that damage opponents and fires her Laser Beam Attack that deals heavy damage and knockback.
In Super Smash Flash 2, Mother Brain is a common Assist. She summons Rinkas that bounce and deal flame damage on contact. Her eye also can rapidly change colors for about 2 seconds and then fire a colorful beam called the Laser Beam Attack that deals heavy damage (81%) and knockback in multiple hits. The beams are extremely accurate, and you can only dodge them by spot dodging, air dodging or shielding. Power shielding reflects the beam right back at Mother Brain. Players can also stand on her tank as if it was another platform. She can be attacked, but she has very high durability. When she is defeated, she explodes.
Mother Brain can also be encountered as a boss in event #40, The Mother Brain. In this event, the player must defeat Mother Brain, who has 200 "hit points" (HP), using Samus in the stage Tourian. Mother Brain maintains the AI she has as an Assist. Additionally, her beams, when reflected at her, will deal immense damage.