swamp dog
One who is so crazy wierd that they seem to creep instead of walking, or laugh instead of talking, who, if aproached you and asked where a member of your family was, would make you want to run away and take a shower. The creepiest of land mammals, the dirtiest of men.
Dave: Man, that Beatty kid is a real swamp dog, creepin' round an' such.
Mike: Shit, I'm goin' home.