Bluish grey above, paler below with a silvery sheen; fins blackish brown. Adults are typically dark brown to slate-grey with whitish tips on the tail lobes. Juveniles have an irregular mottled pattern, a whitish margin on their tail, and black blotches on head and body. Body tall, compressed. Big mouth with big head and a rough bony ridge across upper part of the gill cover. They are known for their large head, big mouth, and a rough bony ridge across the upper part of the gill cover.

It looks like Polyprion oxygeneios (Hāpuku/Two-tone wreckfish), as they are both large, long-lived fish, with similar sizes and weights. Can be distinguished by its slenderer body shape and triangular caudal fin.