This is a classic:
Now there is this bar, dim, slightly smoky place, a bit grimy, you get the idea, cone of light streaming from the ceiling lamp, broken piano in the corner, a guy behind the bar cleaning some glasses with a towel and a barmaid serving a few guests. The door opens, and in walks a panda with a bag; he walks over, slowly, to a corner table, sits down heavily, waves for the barmaid, orders something to eat. So she gets him a steaming plate, and he eats noisily, munching for some twenty minutes, then he waves again and reaches for his bag. So she walks over and gets out her notepad to take the bill, and at the same moment he takes out a huge revolver and shoots the barmaid straight in the chest two or three times: BANG! BANG! BANG!
The barmaid drops dead instantly, and the panda looks at his smoking gun, puts it back into his bag lazily and gets up. As he turns towards the door, the barman, who has been standing in shocked silence, yells after him:
"What the hell was that for?"
And the panda turns around, tosses him a book and walks out. The barman opens the book with trembling fingers and finds that it's an encyclopaedia, with a bookmark sticking in it. So he opens it at the page with the bookmark and reads:
"Panda. Eats, shoots and leaves."