Shell medium sized for the genus, up to 17-18 mm in length at maturity (holotype), heavy, moderately spinose. Spire high with 1.5 protoconch whorls and up to 5 broad, angulate. weakly shouldered teleoconch whorls. Suture impressed, partially obscured by small axial lamellae. Protoconch small, globose, whorls rounded; terminal varix unknown (eroded) Axial sculpture of teleoconch whorls consisting of 4 or 5 high, strong, broad, rounded varices from first to last whorl; varices more developed on shoulder. Spiral sculpture of high, strong, squamous cords: two spiral cords on early whorls; last whorl with 5 cords, ending as short spinelike projections on varices; last whorl occasionally with minor spiral threads. Aperture small, ovate; columellar lip narrow, flaring, smooth, rim partially erect, adherent at adapical extremity; anal notch obsolete; outer lip erect, crenulate, with 4 or 5 weak, occasionally obsolete, lirac within. Siphonal canal moderately long, broad, straight, abaperturally recurved at extremity, narrowly open, with 3 or 4 frondose. short spinelets. Creamy-white, occasionally with light tan blotches on spiral cords or shoulder; aperture white. Operculum dark brown, ovate, with terminal nucleus. Radula unknown.

Favartia deynzeri is highly distinctive from any other Indo-West Pacific or Red Sea species of Favartia by its form, sculpture and particular ornamentation of the siphonal canal. F. cyclostoma (Sowerby, 1841) and F. sykesi (Preston, 1904) which superficially resemble F. deynzeri. have a larger and broader shell, with more numerous, narrower varices, and narrower, larger siphonal canal with different ornamentation

Red Sea. Shab Shareer Egypt, taken alive at 15-20 m.