scum bag
n : 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'" [syn: {rotter}, {dirty dog},
{rat}, {skunk}, {stinker}, {stinkpot}, {bum}, {puke}, {crumb},
{lowlife}, {so-and-so}, {git}]