Do you know ghouls from goblins and ghosts?
large, ferocious bird of fable, 1570s, from Arabic rukhkh, from Persian rukh. Mentioned in Marco Polo's account of Madagascar, modern use is mostly from "Arabian Nights." Hence roc's egg "something marvelous or prodigious."
gigantic legendary bird, said to carry off elephants and other large beasts for food. It is mentioned in the famous collection of Arabic tales, The Thousand and One Nights, and by the Venetian traveler Marco Polo, who referred to it in describing Madagascar and other islands off the coast of eastern Africa. According to Marco Polo, Kublai Khan inquired in those parts about the roc and was brought what was claimed to be a roc's feather, which may really have been a Raphia palm frond.