Freebooter
Freebooter , noun
[Dutch vrijbuiter, from vrijbuiten to plunder; vrij free + buit booty, akin to English booty. See Free, and Booty, and compare Filibuster.]
One who plunders or pillages without the authority of national warfare; a member of a predatory band; a pillager; a buccaneer; a sea robber. — Bacon