A baboon walks into a bar, and orders a milkshake. The bartender stops cleaning the counter, and stares.

The baboon repeats the order and hands him a ten dollar bill, so the bartender slyly hands the baboon his milkshake.

While the baboon drank his milkshake, the bartender was thinking, "What would a baboon know of money?" So, when the baboon finished, the bartender handed the baboon one dollar change, thinking the baboon wouldn't know better, and pass this by.

So as to make small talk, the bartender said, "We don't get many baboons in here...", to which the baboon said, "Well, at nine dollars a milkshake, it's not surprising!"