A bear walks into a bar in Billings , Montana and sits down. He bangs on the bar with his paw and demands a beer.

The bartender approaches and says, 'We don't serve beer to bears in bars in Billings '

The bear, becoming angry, demands again that he be served a beer.

 The bartender tells him again, more forcefully, 'We don't serve beer to belligerent bears in bars in Billings ...' 

The bear, very angry now, says, 'If you don't serve me a beer, I'm going to eat that lady sitting at the end of the bar.' 

The bartender says, 'Sorry, we don't serve beer to Belligerent, bully bears in bars in Billings '

 The bear goes to the end of the bar, and, as promised, eats the woman. He comes back to his seat and again demands a beer.

 The bartender states, 'Sorry, but we especially don't serve beer to belligerent, bully bears in bars in Billings who are on drugs.'

 The bear looks at him quizzically and says, 'I'm not on drugs.'