Western Pacific: western Philippines, Indonesia, New Guinea, Great Barrier Reef, Vanuatu (sighting), New Caledonia, Caroline Islands, Marshall Islands, Nauru (sighting) and Kiribati (sighting). Recently recorded from Tonga.

A dark chocolate ocular band running in an arc from base of 1st dorsal spine to chin; a narrow white blaze on midline of head profile; thorax dark chocolate; a broad white zone behind ocular bar on trunk; remainder of body yellow-orange. Stout, pungent, venomous spines. Caudal fin only slightly incised. Fully scaled midline of thorax. Preopercular angle 119° (111°-120°). Variable cheek scaling; usually overlapping scales, 8-10 rows deep below center of orbit; occasionally, few scattered scales; area fully scaled from lower edge of orbit 2 angle of mouth. S. vulpinus is very closely related to and possibly the same as S. unimaculatus, which has a large black blotch on the sides beneath the soft dorsal rays.

Sometimes territorial, occurs in coral-rich areas of lagoon and seaward reefs. Usually occurs singly or in pairs, but juveniles and subadults occasionally occur in large schools among Acropora where they feed on algae growing on the dead bases of the coral branches. Capable of inflicting painful stings.