Mole

Mary looks out her kitchen window and sees that a mole has practically destroyed the back lawn, so she tells her husband, Paddy, to go out and kill it and to show no mercy.

After ten minutes, Paddy comes back into the house with an evil grin on his face.

"So," says Mary, "did you drown the mole then?"

"Nah," says Paddy, "much more cruel than that.

Spoiler:

I buried the little alive."