Star KO

A Star KO is a type of KO in which opponents get KO'd by passing the upper blast line, tumbling and falling in the background while screaming or yelling, to eventually disappear as a star. Characters who have above average accelerated falling speed are less susceptible to this then characters with below average falling speeds. This type of KO has been present in all of the Super Smash Bros. games. It was absent from the first Super Smash Flash, but was added to the sequel Super Smash Flash 2.

Origin
As getting Star KO'd in Super Smash Bros. Melee yields the Rocket KO bonus, Star KOs are intended to be a reference to the original Pokémon anime series, where the Team Rocket Trio, recurring villains in the anime, would often be sent flying away into the sky by Pikachu, leaving behind a star when they vanished from sight. The frequency of this gag led to it becoming a recurring trope in Eastern media, with some of Nintendo's own video games later referencing the gag.

Trivia

 * is the only character in SSF2 who has dialogue instead of screaming when Star KO'd, as he says "I'm sorry, dad..." before disappearing.