THESAURUS
demoniac
aliene, bedlamite, borderline case, crackbrain, crackpot, crazed, crazy, dement, demonic, devilish, diabolic, energumen, fanatic, fired, flake, fou, idiot, insane, inspired, kook, loon, loony, lunatic, madman, maniac, meshuggenah, noncompos, nut, phrenetic, raving lunatic, satanic, screwball, serpentine, unhallowed, weirdo
ROGET THESAURUS
demoniac
Demon
N
demon, daemon, demonry, demonology, evil genius, fiend, familiar, daeva, devil, bad spirit, unclean spirit, cacodemon, incubus, Eblis, shaitan, succubus, succuba, Frankenstein's monster, Titan, Shedim, Mephistopheles, Asmodeus, Moloch, Belial, Ahriman, fury, harpy, Friar Rush, vampire, ghoul, afreet, barghest, Loki, ogre, ogress, gnome, gin, jinn, imp, deev, lamia, bogie, bogeyman, bogle, nis, kobold, flibbertigibbet, fairy, brownie, pixy, elf, dwarf, urchin, Puck, Robin Goodfellow, leprechaun, Cluricaune, troll, dwerger, sprite, ouphe, bad fairy, nix, nixie, pigwidgeon, will-o'-the wisp, ghost, revenant, specter, apparition, spirit, shade, shadow, vision, hobglobin, goblin, orc, wraith, spook, boggart, banshee, loup-garou, lemures, evil eye, merman, mermaid, merfolk, siren, satyr, faun, manito, manitou, manitu, possession, demonic possession, diabolic possession, insanity, Maxwell's demon,
demoniac, demonic, demonical, impish, demoniacal, fiendish, fiend-like, supernatural, weird, uncanny, unearthly, spectral, ghostly, ghost-like, elfin, elvin, elfish, elflike, haunted, pokerish, possessed, possessed by a devil, possessed by a demon, demonically.