rotter

nouns

a person who is deemed to be despicable or contemptible
"only a rotter would do that"; "kill the rat"; "throw the bum out"; "you cowardly little pukes!"; "the British call a contemptible person a `git'"
bum, crumb, dirty dog, git, lowlife, puke, rat, rotter, scum bag, skunk, so-and-so, stinker, stinkpot