I first heard this in Pharmacy School in the 1960s from one of my professors who (out of class) used it as an example of how *NOT* to pronounce the name of a certain class of drugs. This one appears a lot on the internet. I have modified it to reflect the original flavor of when I first heard it.
This shaggy dog story is about the thirsty bear who walked into a bar. As he sat down, a dog sat down beside him, and snuggled up to him. Then she whispered in his ear, “Buy me a drink, Big Boy?” The bear was so irritated that he gobbled her up forthwith. Then, when he asked for a beer, the bartender refused to serve him. The bear asked why, and the bartender replied that he didn’t serve beer to druggies.
The bear replied, “What do you mean, druggies?”
The bartender said, “I saw that bar bitch you ate!”