The X Parasite, also known as Unidentified Parasite Creature-X by the Federation and Erris (or perhaps Eddis) by the Chozo, ^{[note 1]} is an extremely hostile, shape-shifting organism native to planet SR388. They appear in Metroid Fusion, Metroid: Samus Returns, Metroid Dread, and the prequel manga.

It went out of its way to defend Samus when it would've been better off just running away from the Omega Metroid. The SA-X probably realized it would die if it remained on the BSL and its only hope of escape was Samus's gunship.

Stick to the low ground and fire charged beam shots directly at the SA-X to destroy it. Your beam must be fully charged to damage it. As it approaches, Space Jump over the SA-X to the other side of the floor while charging your beam, and release the shot when you land.

Samus broke ground early in the gaming world when she debuted in the 1986 game Metroid. Originally players were under the impression that Samus was a male, as the English translation of the instruction manual used male pronouns for her. However, completing Metroid in under five hours revealed Samus to be a young woman.