adversary
aggressor
antagonist
assailer
assailing
assaulter
attacker
attacking
combatant
enemy
foe
foeman
invader
mugger
opponent
opposing party
opposite camp
raider
the loyal opposition
the opposition
offender
wrongdoer
ambusher
avenger
beast
bludgeoner
brute
bully
harasser
harrier
hooligan
iconoclast
lapidator
marauder
nightrider
piranha
predator
raper
rapist
retaliator
roughneck
rowdy
ruffian
savage
shedder
slasher
spiller
stabber
stoner
tough
vulture
wild-cat
wolf
yob
yobbo
yobo
assassin
assault
attackers
confederate
follower
horde
horseman
intruder
murderer
onslaught
pirate
pursuer
villain
warrior
divalent
inhalant
monovalent
tetravalent