A hound dog lays in the yard and an old man in overalls sits on the porch.
"Excuse me, sir, but does your dog bite?" a jogger asks.
The old man looks over his newspaper and replies, "Nope."
As soon as the jogger enters the yard, the dog begins snarling and growling, and then attacks the jogger's legs.
As the jogger flails around in the yard, he yells, "I thought you said your dog didn't bite!"
The old man mutters, "Ain't my dog."