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 (Ref. 37816).