Joke stolen from: Laura's Smaller Funnies

Two kids playing in a lane found a donkey who had died with a hard on. Being the mischievous kind of boys, they cut off the donkey's dick and began brandishing it in the air.

Just then, a police officer on his bicycle came up the lane, and the boys not wanting to be caught with it, tossed it over the wall of the Nunnery.

Sister Agnes and Sister Mary taking their afternoon stroll found the dick in the bushes. "Oh sweet Jesus," says Sister Agnes.

"What's wrong?" asks Sister Mary. "You've gone as white as a sheet."

"It's those dirty protestant bastards," Sister Agnes replies. "They have murdered Father O'Toole!"