Ridley (Metroid)
Ridley's status within the ranks of the Space Pirates is unclear, with some sources stating that he is the leader of the entire Space Pirate race, whereas others portray him as simply the Pirates' military commander or even a mere enforcer within the Pirate military ranks, subservient to Mother Brain or Space Pirate High Command. Regardless, he is consistently depicted as a ruthless and cunning tactician who never passes up an opportunity to bring his considerable ferocity to bear on the battlefield, opting to overwhelm his opponents with an unwavering onslaught of attacks from his mouth, claws, and tail. He is also incredibly cruel, actively taking pleasure in the killing and torment of others; at one point in the official manga he taunts Samus by claiming he may have devoured her mother's corpse after killing her, and a Space Pirate log entry in "Metroid Prime" notes that being the mainstay of the Pirate security force is "a job he will certainly relish."
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.