bestiary (n.)

"medieval treatise on beasts" usually with moralistic overtones, 1818, from Medieval Latin bestiarium "a menagerie," also "a book about animals," from bestia (see beast).

A Latin term for such works was liber de bestiis compositus. Roman bestiarius meant "a fighter against beasts in the public entertainments." Bestiarian (1882), modeled on humanitarian, was a word for "one who advocates kind treatment of animals," especially "anti-vivisectionist," but earlier bestiarianism (1864) had been used as the opposite of humanitarianism in reference to cruel and brutal policies.