Specifically a dog with a hairless rear end. This can be as a result of small fires, excessive scratching or bad fashion sense. It can also be used as a geneal derogatory statement about a person.
2. Hey! Look at that moon dog!
person 2:he wasn't drunk, we just huffed some glue at my crib and he had to leave.
person 1(in napoleon dynamite sounding voice):lucky
Sometimes referred as "Moon-doggy-dog"
He likes to research Korea, he looks like an elf aswell as Kim Jong Il, and he despises "le hutch"
Fatboy-Gandalf : No, that's just Moondog, the moondoggydog
Hutchy : Jamie, shut up. Everyone's gay except me!
Moondog : Hutch, get a fookin haircut foo! I am ex-dicatata of da Korea bitchuz! Lick ma baws nigguh'