bad-tempered, ill-tempered, short-tempered, hot-tempered, quick-tempered, in a (bad) mood, cross, as cross as two sticks
irritable, irascible, tetchy, testy, crotchety, touchy, thin-skinned, scratchy, cantankerous, curmudgeonly, peevish, fractious, waspish, prickly, peppery, pettish, shrewish
grumpy, grouchy, crabbed, crabby, disagreeable, volatile, splenetic, dyspeptic, choleric, bilious, liverish, cross-grained
informal snappish, snappy, chippy, on a short fuse, short-fused
British informal shirty, stroppy, narky, ratty, eggy, like a bear with a sore head
North American informal cranky, ornery, peckish, soreheaded
Australian/New Zealand informal snaky
informal, dated waxy, miffy