(a.) Like a fiend; diabolically wicked or cruel; infernal; malignant; devilish; hellish.

Draconian Mephistophelian Tartarean animal anthropophagous atrocious bad baleful barbaric barbarous beastly bestial bloodthirsty bloody bloody-minded brutal brutalized brute brutish cannibalistic cruel cruel-hearted cursed damnable demoniac demoniacal demonic demonish demonlike devil-like devilish diabolic diabolical evil execrable fell feral ferocious fiendlike fierce ghoulish heinous hellborn hellish infernal inhuman inhumane malefic maleficent malevolent malicious malign malignant monstrous murderous ogreish outrageous ruthless sadistic sanguinary sanguineous satanic savage serpentine sharkish sinister slavering subhuman truculent unchristian uncivilized ungodly unhallowed unhuman vicious wicked wolfish