Paddy was an inveterate drunkard.

The priest met him one day, and gave him a strong lecture about drink, hoping to scare the bejeezus out of him. He said, "If you continue drinking as you do, you'll gradually get smaller and smaller, and eventually you'll turn into a mouse."

This frightened the life out of Paddy. He went home that night, and said to his wife, "Bridget.... if you should notice me getting smaller and smaller, will ye kill that blasted cat?"