An oldie but a goodie

A panda bear walks into a bar and orders some food from the bartender. He sits down and eats his meal. After the panda bear finishes eating, he stands up, pulls out a gun and shoots up the bar. 

As the panda is walking out of the door, the bartender asks him, "What are you doing??" 

The panda bear turns and says, "I'm a panda bear, look it up." 

So the bartender looks up 'panda bear' in the dictionary and finds that it says, "Panda bear: eats chutes and leaves."