Coo is one of Kirby's Animal Friends. It appears in Kirby's Dream Land 2 and 3. He has the same appearances as Kine the Fish and Rick the Hamster.
Coo appears in a few episodes, but he doesn't have a certain episde dedicated to him. He also appears to be friends with Tiff.
(Coo's theme in Kirby's Dreamland 3 will be on Pitch the Bird's page.)