Cock and Bull Terrier

It was very unlikely that Marcus's penis would be found, because after having hacked it from Marcus and taken it back to the house, Rufus didn't know what to do with it. He couldn't transplant it on himself, so he put it in Marcus's freezer, only taking it out to remove incriminating evidence when he went back to his own home. It had completely defrosted, so he tossed it to his mum's Staffordshire Bull Terrier, who disposed of it very eagerly, very fast and totally... out of sight of Rufus’s mum.

Marcus's testicles hadn't been wasted on the dog though!