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.
Ridley (Metroid)
Throughout the series, Ridley has undergone a variety of changes in appearance. In the original "Metroid" title, he was roughly the same size as protagonist Samus Aran and sported a more alien appearance (particularly in official artwork, which depicted him with eight eyes running down the length of his head and a small, lamprey-like mouth). In "Super Metroid", he is larger than in the original title several times over, sporting purplish-brown skin, glowing yellow eyes, chameleonic abilities (possibly explaining his inconsistent skin tone across different games and even within different parts of "Super Metroid"), and an overall body shape that heavily resembles a European dragon. Later games depict him as larger still, and "Other M" departs from previous depictions by giving him a bulky, muscular form in contrast with his skeletal appearance in previous games, along with completely purple skin and flattened jaws resembling a pointed duck bill with a noticeable underbite. Ridley's vocalizations were first depicted in "Super Metroid" and took the form of a predatory screech; later 2D titles instead gave him piercing, high-pitched wails, while 3D installments such as the "Prime" games and "Other M" had him perform monstrous roars. His cybernetic form during the events of the "Prime" series is referred to as Meta Ridley and incorporates various ballistic weapon systems, while a robotic duplicate, Ridley Robot, appears as the final boss in "Zero Mission". While he did not originally appear in "", in the 3DS remake "", Ridley returns as the game's final boss in a new cybernetic form called Proteus Ridley in an attempt to steal the last living Metroid before Samus can deliver it to the Galactic Federation, though he is defeated once more. In the new title of the "Super Smash Bros." series, "Super Smash Bros. Ultimate", he is shown as he was in "Super Metroid", with a darker, purplish tone to his skin and with a size scaled to his original appearance in the first Metroid title, although he has an alternate costume resembling Meta Ridley.