Weasel

A 13 year old weasel walks into a bar and approaches the counter.

The bartender immediately notices the underage weasel. "Sir, you look extremely young. I can't serve you even a single beer".

"Oh c'mon. You can't just slide me one?"

"Can't and will not serve to anyone under age".

"Fine. Well what other things do you have?"

"Well for non-alcoholic drinks I have tap water and bottled water, I have coffee, and I have pop. Which would you like?"

Spoiler:

"Pop" goes the weasel.