The monkey jumps on the counter and gobbles up a bowl of peanuts.
The bartender asked the guy, "Did you see what your monkey just did?"
The guy replied, "Yeah, he does that all the time. He's always hungry. I'll pay for the peanuts", and hands the bartender a buck. The bartender clinks a couple of pennies as change onto the counter, which the monkey promptly grabs and swallows.
The guy said, "Oh he eats random things all the time".
As if on cue, the monkey jumps onto the pool table and stuffs the cue ball down his throat. Sighing, the man brings out his wallet.
The next week, the man and his monkey go back to the bar. This time, the monkey sees cherries on the counter. He grabs one, rams it up his buttcrack, removes it and eats it.
Disgusted, the bartender asks the guy, "Did you see what your monkey just did?"
The guy says, "Yeah, ever since he had to shit out that cue ball he ate last time, he'll be darned if he doesn't measure everything first".