no subject

That is a good question. Perhaps the person who originally said it just didn't like cats? Or, it may be a reference to the Cat Sidhe which was a spirit that often took the shape of a large black cat with a white spot on its chest. Cat Sidhe were said to be able to steal the soul of a person if one passed over the person's body before it was buried. So, if your soul was cursed to be 'eaten' by a Cat Sidhe and then said Cat Sidhe was eaten by the devil, it would be one powerful double curse.

[He has to admit, a curse like that has a lot more impact on him than just the idea of someone being impolite would. Then again, he and curses have a long history together...]