Bucephalus (Gr "ox-headed", from βους, "ox", and κεφαλή, "head") was a type of branding mark anciently used on horses. It was one of the three most common, besides Ϻ, San, and Ϙ, Koppa. Those horses marked with a San were called Σαμφόραι, Samphorai; those with a Koppa, Κοππατίαι, Koppatiai; and those with an ox's head, Βουκέφαλοι, Bucephali.
This article incorporates text from a publication now in the public domain: Chambers, Ephraim, ed. (1728). "article name needed". Cyclopædia, or an Universal Dictionary of Arts and Sciences (first ed.). James and John Knapton, et al.