It is a single-use Copy Ability, and one of the most powerful in the games, being able to hit everywhere on the screen. It first appeared in Kirby's Adventure, where Kirby would freeze everything on the screen in place before flying across the screen erratically at a rapid pace, doing massive damage to everything. In subsequent games, Kirby would simply summon a massive energy surge around him to the achieve the same effect, burning every enemy on-screen to deal massive damage.
Crash Kirby appears in two episodes of Kirby: Right Back at Ya!. It is the one of the only times that Kirby dons a hat for the ability (the only other time is in Kirby's Return to Dream Land; in most games, Kirby just flashes when he has the ability, like with most other one-use abilities). In the transformation sequence, bands of light form the hat that lands on him and changes his color. The hat is a complicated piece with a golden bridge up front with a green gemstone in the center within a starburst decal. A material striped off-white and navy is weaved behind the golden base. It is pulled up and tied off to a nub on the top by a gold band as the rest hangs down in the back. His pink skin turns darker and Kirby's rosy cheeks are changed to an amber shade.
Instead of creating an explosion directly from his body Kirby pulls a white-hot orb of energy out of his mouth, then raises it over his head. The ensuing explosion is unique in that Kirby can choose who it harms so his friends don't get hurt - unlike the Mike ability.
In the anime, it was once mentioned that King Dedede has a fear of the Crash ability.
In Kirby Super Star Ultra, lightning flies from Kirby, and he does a few flips when using the Crash ability.
In Air-Ride-in-Style - Part II, as Kirby transforms into Crash Kirby, Meta Knight tells which ability he gets, even though Meta Knight isn't even on the screen.
In Kirby's Adventure, when Kirby uses the Crash ability, he bounces across the screen at numerous random directions at super-fast speeds, all the while a strobe effect is shown to represent explosions. This scene was never shown in any other game, presumably to prevent epileptic seizures.
For the first time since the anime, this ability has a cap in Kirby's Return to Dream Land. However, this hat looks nothing like the hat seen in Kirby: Right Back at Ya!.