demoniacal
insane
aliene
amok
amuck
bedlamite
berserk
borderline case
crackbrain
crackpot
crazed
crazy
dement
demonic
devilish
diabolic
energumen
fanatic
fired
flake
fou
idiot
inspired
kook
loon
loony
lunatic
madman
maniac
meshuggenah
noncompos
nut
phrenetic
possessed
raving lunatic
satanic
screwball
serpentine
unhallowed
weirdo
demon
devil
fiend
monster
ogre
berserker
bestial
bloodthirsty
fearsome
fiendish
gleeful
hellish
homicidal
impish
malevolent
maniacal
pent-up
superhuman
unearthly
unreasoning
vengeful
vindictive
wolfish