Crocodile

Crocodiles were a species of reptile.

In ancient Egypt, Thoueris controlled the crocodiles in the River Nile with her ring. The Eighth Doctor took her ring and used it to turn the crocodiles against her. (DWM: The Power of Thoueris!)

In 1947 India, a gigantic crocodile tried to attack the Campbells' house, but Major Daker shot it dead. (NSA: Ghosts of India)

On an unnamed planet, the First Doctor was nearly attacked by a crocodile, but drove it off. (TVC: The Didus Expedition)

One planet was inhabited by six-legged, telepathic crocodiles. (DWA: The Crocodiles from the Mist)