Eats, Shoots and Leaves
A panda walks into a café. He orders a sandwich, eats it, then draws a gun and proceeds to fire it at the other patrons.
"Why?" asks the confused, surviving waiter amidst the carnage.
The panda pauses on his way out, produces a badly punctuated wildlife manual, and tosses it over his shoulder.
"Well, I'm a panda," he says at the door. "Look it up."
The waiter turns to the relevant entry and, sure enough, finds an explanation:
"Panda. Large black-and-white bear-like mammal, native to China. Eats, shoots and leaves."
Source: Good joke: Eats, Shoots and Leaves