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."
Transformers: Prime
The Decepticons are led by Megatron (Frank Welker), who is the main antagonist throughout the series. Initially, he is assisted by his loyal follower the silent Soundwave, and the treacherous Starscream (Steven Blum) who wishes to usurp him. Later, they are joined by Knock Out (Daran Norris)—the Decepticons' medic—and his partner Breakdown (Adam Baldwin), who has an ugly past and a rivalry with Bulkhead. Soon afterward, Airachnid (Gina Torres) comes into play as well; before her introduction, she had killed Arcee's first partner Tailgate.