Planet (The Didus Expedition)

An Earth-like planet was the location of a zoo which was near a jungle. The zoo exhibited a didus, a mammoth, a stegosaurus, and a tyrannosaurus rex (or, at least, creatures that resembled these species). The jungle was home to crocodiles, monkeys, snakes and a hostile tribe.

The First Doctor, John and Gillian arrived on this planet, where they visited the zoo and met the zookeeper and his bush baby. Upon finding that the didus had escaped, they volunteered to go into the jungle to find it and bring it back. After doing so, the zookeeper showed them his recently acquired pterodactyl and the newly-hatched didus chicks. (COMIC: The Didus Expedition)

Behind the scenes
Although some sources claim that the planet's name is "Animalia", based on the sign that appears in the first panel of this story, this is more likely the use of the Latin word for animals, just as didus is Latin for dodo.