scummy (
http://definr.com/scummy)
adj 1: of the most contemptible kind; "abject cowardice"; "a low
stunt to pull"; "a low-down sneak"; "his miserable
treatment of his family"; "You miserable skunk!"; "a
scummy rabble"; "a scurvy trick" [syn:
abject,
low,
low-down,
miserable,
scurvy]
2: covered with scum; "the scummy surface of the polluted pond"