Mother Brain utilized it against Samus Aran during their Final Conflict. While having a slow startup time to charge, is seemingly the strongest weapon the Pirate leader has ever used. It is a conical, multicolored, flashing beam that makes Mother Brain shift colors as well.
It is unavoidable, and will drain three of Samus's Energy Tanks (6 if the Varia Suit is not equipped), all of her Super Missile and Power Bomb Ammo, and 75 Missiles in one shot. After being attacked with the beam, Samus can use her remaining Missiles against Mother Brain until she either depletes them or is attacked again. If Samus does not have 3 Energy Tanks (or 6 without the Varia Suit) remaining when Mother Brain first uses the attack, then the blast will eventually kill her, resulting in a Game Over. After the attack is finished, if Samus does not have enough energy to withstand another blast, she will not be able to move. If she does have enough energy, Mother Brain will simply use the attack again. Eventually, the shots will become so frequent that Samus will not be able to move between them.
Once Samus has been rendered helpless, Mother Brain will throw a few projectiles at her, then starts charging one final Laser Brain Attack before the baby comes to Samus's rescue. The baby seemingly absorbs the blast of the weapon at the same time she is firing it, given the fact that Mother Brain is shifting colors while the Metroid is latched onto her. Mother Brain no longer uses the Laser Brain Attack afterward, presumably as a result of being damaged and/or the baby having absorbed the energy (or the actual beam) required to fire it. It is implied that the visually-similar Hyper Beam received by Samus uses the energy drained from the Laser Brain Attack.
In the prologue of Metroid: Other M, it is possible that the Laser Brain Attack appears as Mother Brain's fatal blow to the Metroid baby, although this directly contradicts the events seen in Super Metroid. Considering that the cutscene never shows Mother Brain directly firing the Laser Brain Attack at Samus, it is impossible to tell whether it is truly the actual Laser Brain Attack or not.
In this cutscene, Mother Brain appears to be charging energy for a moment before she fires an orange beam from her eye that pierces the Metroid. Mother Brain also seems to glow briefly, like she did when using the Laser Brain Attack in Super Metroid, although the glow is also orange. If the attack was the Laser Brain Attack, then the attack was changed from a conical, color-shifting ray to a more focused, plain orange beam.
Alternatively, Mother Brain was also capable of firing another weaker type of energy attack from her eye in Super Metroid, which could have been the attack depicted in this cutscene instead. However, this weaker attack resembled the beams fired by Zebesians in Super Metroid, while the Zebesians' beams do not resemble Mother Brain's attack at all in Other M.
As confirmed by Masahiro Sakurai, the Laser Brain Attack returns in Super Smash Bros. for Nintendo 3DS and Wii U and Super Smash Bros. Ultimate as the Assist Trophy Mother Brain's attack. She uses this attack while still in her Control Capsule, which is shattered by the beam. It retains its Super Metroid sound effects and visual appearance. The devastating Laser Brain Attack can deal up to 90% damage, although its knockback is not very strong.
- Even with the Gravity Suit enabled, it is the Varia Suit that lowers the damage from the Laser Brain Attack. When the Gravity Suit is worn without the Varia or neither Suit is worn, the Attack drains six Energy Tanks, but the number is reduced to 300 with only the Varia Suit enabled. This is odd given that the Gravity Suit is supposed to reduce damage even further than the Varia Suit.
- Given that Mother Brain was said to have created Samus's Power Suit in the Magazine Z manga, it is possible that the Laser Brain Attack was engineered specifically to counter Samus' Power Suit.
- The brain blast attack used by Mother Brain in Metroid: Zero Mission can be considered a retroactive precursor to the Laser Brain Attack.