This large, sleek, but robust fish has a blunt snout, with a flat bridge between the eyes. The body color is predominantly olive to dark green on top, while the underside is paler. There appears to be two distinct populations of this species in the Indian Ocean, with the members of the first growing much larger than those of the second. The upper part of the snout and the region between the eyes are scale-less. The fins are well developed and include a single dorsal of ten spines plus 11 rays, an anal of three spines plus 8 rays, and a deeply forked caudal fin with pointed lobes. The pectoral fins are short and almost equal to the length of the snout. The mouth is large, with fine bands of teeth in each jaw, and several large canines at the front. The moderately large eyes are preceded by a distinct horizontal groove.

The adult green jobfish can reach a size of 110 cm in length. The green jobfish is a common and powerful predator of tropical and sub-tropical regions. It ranges from shallow coastal waters to depths of 100 m, but is more commonly found between mid-water and the surface, directly above coral and rocky reefs. Though usually solitary, the green jobfish does occasionally form loosely packed schools which hunt swiftly over extensive areas of reef, especially at night. It may occur close to the seabed during daylight. Small reef fish comprise about 50 per cent of its diet, but much of the balance is made up of plankton, including organisms such as fish eggs, larval mantis shrimps, megalopa crab larvae and swimming crabs. Spawning occurs in tropical East African waters from January to May, and the juveniles have been recorded far from land, borne by ocean currents. Sexual maturity is reached at a length of 70-75 cm, equivalent to 3-4 years of age.