Didus

The didus was a rare species of bird native to an unnamed planet. It had been thought extinct for centuries until one animal collector acquired a live didus and several didus eggs. This didus escaped shortly before the First Doctor, John and Gillian came to visit the zoo. The travelers offered to find the bird and set off into the jungle, where they encountered a hostile tribe who had captured the didus, believing it to be lucky. The Doctor tricked the tribesmen with a false bird and returned the didus to the zoo. (TVC: The Didus Expedition)