Any breed of large, mean looking dog such as an American Bulldog, Pitbull, Staffordshire Terrier, etc. These dogs are known for brute strength and tough looking appearance, however they are really just loveable little goofs.
Danielle: I was walking the dog this morning and I saw another Doofus in the neighborhood, except he was solid white.
The pinnacle of being a blonde; a girl with no clue; oftentimes nieve (though sometimes in an endearing way); a person who likes bad basketball teams, any girl named Katie.