The roc was giant bird that rumorly lived lived in arabia. It was made famous its apperance in the story sinbad the sailor. In it, Sinbad is stuck in a vally when a roc flys over it. Sinbad clings to its claws and makes his escape. the roc does not make aperrence on the show, but its relative the raicho appears in comic book The Storm That Shook Japan.
A giant Ratite called Aepyornis, more commenly as the Elepant bird that roamed Prehistoric Madagascar is often claimed to be the source of the legend as a disorted verson of it.