Ridley (Metroid)
Often considered one of the most memorable Nintendo villains, Ridley has been a mainstay of the series, having appeared (through various incarnations) in almost every "Metroid" game to date (all but "", "Metroid Prime Hunters" and ""). He has also appeared in the "Super Smash Bros." series, however, he had not been made a playable character until "Super Smash Bros. Ultimate" in 2018, making it also the first game overall to have Ridley as a playable character.
Metroid
"Metroid" was designed to be a shooting game that combined the platform jumping of "Super Mario Bros." with the non-linear exploration of "The Legend of Zelda" and a distinctly darker aesthetic. The name of the game is a portmanteau of the words "metro" (as in rapid transit) and android, and was meant to allude to the mainly underground setting of the first game as well as its robot-like protagonist. Halfway through development of the original "Metroid", one of the staff said to his fellow developers "Hey, wouldn't that be kind of cool if it turned out that this person inside the suit was a woman?", and the idea was accepted. Ridley Scott's 1979 science-fiction horror film "Alien" was described by Sakamoto as a "huge influence" after the world of the first "Metroid" had been created. The development staff was affected by the work of the film's creature designer H. R. Giger, and found his creations to be fitting for the "Metroid" universe. In recognition of this, a character was given the name Ridley, after director Scott.