I told this one in a thread, so bear with me.

A bear walks into a bar and orders a beer. The bartender takes one look at him and says
"We don't serve bears, please leave."
The bear replies "give me a beer or shit is going to get real ugly!" The bartender retorts "I told you once I told you enough; gtfo." Our bear spots the local barfly sitting on a stool down the way so he walks over and eats her up in one giant bite. GULP.
"Buddy, you're next." He says to the barkeep. "Now get me a beer."
Bartender changes his tune after the grizzly display that he just witnessed and says
"I'm sorry sir, we cannot serve you since you are on drugs."
"On drugs?! Queries the bewildered bear.
"I haven't done drugs since . . I don't do drugs!"
"Oh yeah? What about that bar bitch you ate?"