skulker

noun4

1. •
   Agent noun of skulk; one who skulks.
2. •
   One who stays where they cannot be seen (often in a cowardly way or with the intent of doing harm).

   • Our men, from their position, can’t see these skulkers, who will have a good chance to pick off some of them at their leisure. — 1894
3. •
   One who moves in a stealthy or furtive way; one who comes or goes while trying to avoid detection.

   • Afterwards he was again taken by Ethiopian Skulkers, and carry’d away into the Maritime Parts of Ethiopia. — 1700
4. •
   One who avoids an obligation or responsibility.

   • John himself was no skulker in joy. He not only bestowed on Mr. Morland the high commendation of being one of the finest fellows in the world, but swore off many sentences in his praise. — 1803