Pterygotrigla arabica is characterized by a moderately large head devoid of scales but featuring numerous ridges and spines. The anterior end of the snout has two outward-pointing spines, and robust triangular spines are present on the rostrum. An elongated, thin spine on the operculum extends beyond the cleithrum, which bears a shorter spine. The terminal mouth is equipped with small villiform teeth on the jaws, mandibles, premaxilla, and vomer. Elongated scales cover the trunk, excluding the ventral surface, except for the belly. The first dorsal fin has 7 spines, the second dorsal fin has 12 soft rays, and the anal fin has 12 soft rays. The pectoral fin comprises 12 rays within its fin membrane and 3 separated rays. The overall coloration is red with irregular black spots on the head, upper body, and soft-rayed dorsal fin. A prominent black spot is present on the spiny dorsal fin, and the inner surface of the pectoral fin is also black.