Bar joke

A guy walks into a bar with his pet alligator, puts the gator up on the bar, and faces the patrons. "If I open this alligator's mouth and put my balls inside, leave 'em there for five minutes, then remove 'em unscathed, will each of you buy me a drink?" The crowd murmurs its approval, so he gets up on the bar, drops his pants, and puts his balls into the alligator's mouth. The gator then closes his mouth as the crowd gasps.

After five minutes, the man grabs a beer bottle and raps the alligator hard on the top of his head. The gator opens its mouth and the man removes his genitals - unscathed, as promised. The crowd cheers, and the first of his free drinks is delivered. "Anyone else have the guts to give it a try?" the man dares the crowd. After a few seconds, a guy in the bar speaks up. "I'll do it, but no hitting me on the head with the bottle."