Same word as petulant:

bad-tempered, captious, caviling, complaining, cranky, cross, crybaby, displeased, fault-finding, fractious, fretful, grouchy, grumbling, huffy, ill-humored, impatient, irritable, mean, peevish, perverse, pouting, querulous, snappish, sour, sulky, sullen, testy, touchy, ungracious, uptight, waspish, whining, whiny