WordNet sense 1 (characteristic of an enemy or one eager to fight):

belligerent

WordNet sense 2 (tending to spread quickly):

fast-growing, strong-growing

WordNet sense 3 (marked by a tendency to spread especially into healthy tissue):

invasive

WordNet sense 4 (ready and able to resort to force or violence):

pugnacious

WordNet sense 5 (living by preying on other animals especially by catching living prey):

rapacious

WordNet sense 6 (showing a fighting disposition):

militant

WordNet sense 7 (having or showing a ready disposition to fight):

bellicose, combative