Johnny is sitting in a biology class, and the teacher says that an interesting phenomenon of nature is that only humans stutter, no other animal in the world does this.

Johnny's hand shoots up. "Not correct Miss" he says!

"Please explain Johnny" replies the teacher?

"Well Miss. The other day I was playing with my cat on the step. The neighbors Great Dane came around the corner, and the cat went "ffffffffff, ffffffffffff, ffffffffff" and before he could say "Fuck off" the dog ate him.