Mycteroperca xenarcha has an elongated, robust and compressed body which has its depth at the origin of the dorsal fin is not any greater than the depth at the origin of the anal fin. The snout is much longer than the eye with the lower jaw projecting beyond the upper and with canine-like teeth at front of the jaws. The preopercle corner angle strongly serrated and there are 29-33 gill rakers. The dorsal fin has 11 spines and 16-17 soft rayes with spines 2-7 being the same length; the anal fin has 2 pines and 10-11 rats, the pectoral fin has 16-18 rays, although most specimens have 17. The caudal fin has a jagged rear edge caused by the projecting of the rays beyond the membrane. It is pale brown in colour with elongated dark brown blotches, which frequently have pale brown middles. It grows to about 150 cm in length and to 45.4 kg in weight. The record catch is 49.2 kg.
