Ostrich

The ostrich was a large, flightless bird native to Earth. By the year 5,000,000,000, all that remained of this species was an egg in the possession of Lady Cassandra, which actually contained a feed used to enhance her teleport signal. Lady Cassandra said that the ostrich had a fifty-foot wingspan and could shoot fire out of its nostrils. (TV: The End of the World)

Behind the scenes
According to non-narrative source Monsters and Villains, the ostrich became extinct in 2051.