feral
ferine
savage
semi-wild
unbroken
undomesticated
Gothic
Neanderthal
animal
atrocious
barbarian
barbaric
barbarous
bestial
bloody
brutal
brutish
ferocious
fierce
ill-bred
impolite
inhuman
kill-crazy
malign
malignant
merciless
murderous
noncivilized
outlandish
pitiless
primitive
rough-and-ready
ruthless
sanguinary
tameless
troglodytic
uncivil
uncivilized
uncombed
unconquered
uncontrollable
uncouth
uncultivated
uncultured
unenthralled
ungentle
ungoverned
unkempt
unlicked
unpolished
unquelled
elemental
impetuous
intractable
lawless
mettlesome
primeval
restive
trackless
undisciplined
ungovernable
unrestrained
unruly
unspoiled
untutored
warlike
wild