Talking Dog In A Bar

A guy walks into a bar with a dog under his arm, puts the dog on the bar and announces that the dog can talk and that he has $100 he's willing to bet anyone who says he can't. The bartender quickly takes the bet and the owner looks at the dog and asks, "What's the thing on top of this building which keeps the rain from coming inside?" The dog answers "ROOF." The bartender says, "Who are you kidding? I'm not paying." The dogs owner says, "How about double or nothing and I'll ask him something else". The bartender agrees and the owner turns to the dog and asks, "Who was the greatest ballplayer of all time". The dog answers with a muffled "RUTH." With that the bartender picks them both up and throws them out the door. As they bounce on the sidewalk the dog looks at his owner and says "DiMaggio?".