Crocodile

Crocodiles were a type of reptile known to reside on several different planets.

On Earth
The Sarcosuchus was an ancient species of Earth crocodile. (AUDIO: Spring-Heeled Jack, Family Matters)

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. (COMIC: The Power of Thoueris!) According to the Twelfth Doctor, the people of Crocodilopolis in ancient Egypt worshipped a giant crocodile, which the Doctor claimed was a "useful coincidence". (TV: The Caretaker)

According to the Legend of Sutekh, they were among the animals associated with the titular Osiran god of evil and violence, Sutekh. Other animals associated by the Egyptian tradition with the cults of Sutekh included donkeys, hippopotamuses and pigs. (PROSE: Background)

Near the Karabar Caves, India on 31 December 1926, the Fifth Doctor and his companions Nyssa, Tegan Jovanka and Turlough were forced to cross a den of crocodiles. Tegan referred to one of them as "an overgrown handbag." (AUDIO: The Emerald Tiger)

In India in 1947, a crocodile which had been mutated by zytron energy tried to attack Edgar Campbell's house, but Major Daker shot it dead. (PROSE: Ghosts of India)

On other planets
On an unnamed planet, the First Doctor was nearly attacked by a crocodile, but drove it off with some magnesium powder. (COMIC: The Didus Expedition) A lake on one planet was infested with crocodiles. The first of the tests of Trefus required that one of the fair-haired people to swim across this lake. Saul completed this test when the Second Doctor used explosives to temporarily stun the crocodiles. (COMIC: The Tests of Trefus)

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

Crocodiles lived on an island in the Divergent Universe. (AUDIO: The Next Life)

Similar species
The soresox were a species that looked like stone crocodiles. (PROSE: The Doctor Trap)

A crocodilian species was native to Sobek. (AUDIO: The Skull of Sobek)