Priacanthus hamrur, the lunar-tailed bigeye, goggle eye, or moontail bullseye, is a species of marine fishes belonging to the family Priacanthidae.

Distribution This species is uncommon but widespread in the Indo-Pacific, from the Red Sea and southern Africa to French Polynesia, southern Japan, and Australia. It has been reported also from Easter Island. Two records have been reported from the Mediterranean Sea off Tunisia and Turkey respectively.

Habitat Priacanthus hamrur is a reef-associated species, living in tropical marine waters on outer reef slopes and rocky areas and in lagoons at depths of 8 to 250 meters (26 to 820 ft), but most commonly from 30 to 50 m (100 to 160 ft).

At sexual maturity the size of Priacanthus hamrur reaches 18–19 cm (7.1–7.5 in) in males, 19.1–20.0 cm (7.5–7.9 in) in females, but males can reach a maximum length of 45 cm. The body of the crescent-tail bigeye is relatively deep, strongly compressed laterally. The eyes are very large and red (even in case of silver livery). The mouth is oblique with a protruding lower jaw and small conical teeth. The extremity of the lower lip is above the median line of the body.