Chicken Boo
From Loonipedia
Chicken Boo is a character on the show Animaniacs.
He is an oversized chicken who tries to mock humans with obvious disguises. Most people cannot see though his obvious disguise, but a few people can. In the end Chicken Boo ruins his cover by doing something that rips or makes it slide off. He is voiced by Frank Welker and is not to be confused with Foghorn Leghorn.