Ridley (Metroid)
Ridley returns in his Meta form once again in "", where he, along with the Space Pirate legion under his command, are corrupted by Dark Samus. He encounters and battles Samus on Norion, a Galactic Federation-occupied world, and the two fight while free-falling down an air shaft. Ridley is later supercharged with Phazon, becoming "Omega Ridley", and is charged with guarding the Leviathan Seed on the Space Pirate homeworld. He is confronted once again by Samus, and despite being defeated, he survives the fight and is later cured of his corruption after Dark Samus' defeat later on. Between the "Prime" trilogy and "", the Space Pirates reorganize on Zebes and hatch another plan to clone and weaponize the Metroids, while Ridley gradually begins to regenerate from his past injuries, gradually shedding his cybernetics. In the remake of the second game, "", Ridley, in his semi-regenerated form of "Proteus Ridley", attacks Samus on SR388 to steal the last remaining Metroid. Samus and the baby Metroid work together to defeat Ridley.
Metroid: Zero Mission
Space Pirates attack a Galactic Federation-owned space research vessel and seize samples of Metroid creatures. Dangerous floating organisms, Metroids can latch on to any organism and drain its life energy to kill it. The Space Pirates plan to replicate Metroids by exposing them to beta rays and then using them as biological weapons to destroy all living beings that oppose them. While searching for the stolen Metroids, the Galactic Federation locates the Space Pirates' base of operations on the planet Zebes. The Federation assaults the planet, but the Pirates resist, forcing the Federation to retreat. As a last resort, the Federation decides to send a lone bounty hunter to penetrate the Pirates' base and destroy Mother Brain, the mechanical life-form that controls the Space Pirates' fortress and its defenses. Considered the greatest of all bounty hunters, Samus Aran is chosen for the mission.