The pygarg is an animal mentioned in the Bible

Bible

The Bible refers to any one of the collections of the primary religious texts of Judaism and Christianity. There is no common version of the Bible, as the individual books , their contents and their order vary among denominations...

 in Deuteronomy

Deuteronomy

The Book of Deuteronomy is the fifth book of the Hebrew Bible, and of the Jewish Torah/Pentateuch...

 14:5, as one of the animals permitted for food. The Septuagint translates dishon as pygargos (meaning "white-rumped") and the King James Version takes from there its term "pygarg."

Henry Baker Tristram

Henry Baker Tristram

The Reverend Henry Baker Tristram FRS was an English clergyman, Biblical scholar, traveller and ornithologist.Tristram was born at Eglingham vicarage, near Alnwick, Northumberland, and studied at Durham School and Lincoln College, Oxford. In 1846 he was ordained a priest, but he suffered from...

 (1867) proposed it to be the antelope Addax

Addax

The Addax , also known as the screwhorn antelope, is a critically endangered species of antelope that lives in the Sahara desert. As suggested by its alternative name, this pale antelope has long, twisted horns. It is closely related to the oryx, but differs from other antelopes by having large...

. It is described as "a large animal, over 3½ feet high at the shoulder, and, with its gently-twisted horns, 2½ feet long. Its colour is pure white, with the exception of a short black mane, and a tinge of tawny on the shoulders and back.".