Coo's Forest is the fourth stage in Kirby Fighters and Kirby Fighters Deluxe, and also appears in Kirby Fighters 2. The arena is based on the fifth stage in Grass Land in its appearance in Kirby's Dream Land 3.
Coo's Forest uses the pastel-aesthetic of Kirby's Dream Land 3. It features three trees, each with two platforms on them, separating the area into high, middle, and low regions. On the left and right trees are holes in the high and low regions, with the middle tree having a hole in the middle region. The main hazards of the stage are the Animal Friends from Kirby's Dream Land 2; Coo, Rick, and Kine can emerge from these holes and interfere with the fight. Players can be damaged by coming in contact with the Animal Friends, as well as being hit by their own attacks. Coo appears the most often, and attacks using the Cutter combination, throwing out three feathers twice. When Rick appears, he attacks with his Burning combination, shooting a stream of flames out of his mouth. Kine is the least common, and upon appearing, simply flops in place instead of performing an attack based on a Copy Ability; however, he still damages players who come in contact with him. The music that plays here is called "Four-Way Fight in Coo's Forest," a medley of Coo's theme and Rick's theme from Kirby's Dream Land 2.