Cook Kirby is one of Kirby's copy abilities from his series of games and is his Final Smash in Super Smash Bros. Brawl. Kirby puts on a chef's hat and "rings" a frying pan. Everything on screen (items and players) is sucked into the pot and cooked, 2% to 5% Each Hit. taking massive damage Afterwords. After a while, the players and various items are shot out. While powerful (about 34% damage), it has the potential drawback of allowing those hit by the attack to use the items that come out with them.
Interestingly, the Japanese update for the move featured a song that apparently plays while Kirby is cooking, while other languages did not. The song is from a Japan-only game, so the reference would likely have been missed by players outside of Japan.
The move is based on Kirby's Cook ability from Kirby Super Star. While not able to damage bosses like other one time use powers, it was able to suck in all minor enemies to turn them into healing food items.