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, as the panda makes towards the exit. The panda 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 in the manual and, sure enough, finds an explanation. 'Panda. Large black-and-white bear-like mammal, native to China. Eats, shoots and leaves.'
I love this joke.