From the Super Mario Wiki
The title of this article is official, but it comes from a non-English source. If an official name from an English source is found, the article should be moved to its appropriate title.
Coo Coos are hen-like creatures that only appear in Super Mario Sunshine. They resemble large chickens with two beady eyes, with a star around one. They first make an appearance in Bianco Hills, where they fly around randomly and drop splotches of Graffiti whenever they get near Mario. They later appear in Episode 3 of Pianta Village, where they drop Lava Goop. Coo Coos can be defeated by jumping on them or spraying them to the ground with F.L.U.D.D.. Coos Coos release several Coins with each spray, up to a 1-Up Mushroom.
- Cluckbooms, enemies that look similar to Coo Coos, appear in Super Mario Galaxy, and its sequel, Super Mario Galaxy 2. Their method of attacking Mario is by dropping Bombs on him, similar to a Coo Coo's method of dropping Goop on Mario.
- Their name is based on the cuckoo, a kind of bird.