A roc or rukh (from Persian رخ rokh, asserted by Louis Charles Casartelli to be an abbreviated form of Persian(simurgh) is an enormous legendary bird of prey, often white, reputed to have been able to carry off and eat elephants. Although, many aspiring scholars and teachers have proven this thought wrong; these birds are no larger than the ancient pterodactyl, which was about two times as large as the common bald eagle.

Eastern Orgins
The roc had its origins, according to Rudolph Wittkower, in the fight between the Indian solar bird Garuda and the chthonic serpent Nāga, a word that A. de Gubernatis asserted signified 'elephant' as well as 'snake' The mytheme of Garuda carrying off an elephant that was battling a tortoise appears in two Sanskrit epics, the Mahabharata (I.1353) and the Ramayana (III.39). The roc appears in Arabic geographies and natural history, popularized in Arabian fairy tales and sailors' folklore. Ibn Battuta (iv. 305ff) tells of a mountain hovering in air over the China Seas, which was the roc.