Okay, so the deal is, I'm this ancient hero. Cu Chulainn. It means "Hound of Culann". You see, when I was a kid, I killed this hellhound that wanted to eat me, but the owner was pretty sad about his dog dying. So I decide, what the fuck, I'll make it up to him, and I train another dog to take the first one's place. Of course, he needs someone to guard his house while I'm training the dog, so I took the dog's place. The man's name was Culann, so from then on, everyone called me Cu Chulainn.

[A pause.]

And some people have seen fit to turn it into a joke involving dogs.