slimeball

Short definition from Wiktionary

Noun

1. 1
   A round lump made up of or coated with slime or a slime-like substance such as mucus.
2. 2
   A round lump made up of or coated with slime or a slime-like substance such as mucus: A mucus-coated lump containing the cercariae (“parasitic larvae”) of a liver fluke (of the phylum Platyhelminthes).
3. 3
   A person who is slimy (that is, sneaky or underhanded) or otherwise undesirable.