acrimonious

disaffected, discontented, disgruntled, malcontent

contemptuous, cynical, disdainful, misanthropic, scornful

angry, cruel, harsh, irritated, mad, rough, savage, vehement, vicious, virulent, vitriolic

acid, caustic, cutting, mordant, sarcastic, trenchant

knock-down, drag-out (or knock-down-and-drag-out)