Physiologus de naturis duodecim animalium.

The earliest printed edition (circa 1482) of the Physiologus, a Christological natural historical work that originated in Late Antiquity, and remained popular through the Middle Ages. This edition, which was very widely used as a school text, sometimes provided with a commentary, during the Middle Ages, was attributed to a bishop Theobaldus, who may have been Abbot of Montecassino from 1022-1035. ISTC No. it00142000.

English translation: Physiologus: A metrical bestiary of twelve chapters by Bishop Theobald printed in Cologne 1492. Translated by Alan Wood Rendell. London: John & Edward Bumpus, Ltd., 1928. Digital facsimile from Bestiary.ca at this link. The Theobaldus version was retranslated and edited by P. T. Eden as Theobaldi "Physiologus" (Leiden: E. J. Brill, 1972).