Crocodile in a Bar

A guy walks into a bar with a crocodile.
The barman goes, "You can't bring that animal in here!"
But the guy goes, "Hey, he does tricks. Watch!"
He taps on the crocodile's head, and the beast opens its mouth. The guy unzips his pants, whips out his vulnerable member, and puts it in the crocodile's mouth. Then he taps on the crocodile's head again, and the beast closes its mouth. Everyone in the bar is aghast.
The guy gets his penis out, and he goes, "I'll give 100 bucks to anyone who can do that."
Everyone is really, really quiet. Suddenly, a drunk shouts, "I.. . I think I can do that. But I don't think I can leave my mouth open that long!"