The Chlorisians are the native humanoid species from the jungle world known as Chloris, and are externally indistinguishable from Humans. They have domesticated the native Wolfweeds and use them as hunting "animals".
At the time the Fourth Doctor visited the planet, the Chlorisians were a relatively primitive civilization. They were ruled by Lady Adrasta, who used manipulation of superstition and her monopoly over the extremely rare metal resources of the planet to maintain her power.
When the Tythonian ambassador Erato visited the planet to offer a trading route (as Tythonus was very rich in metal and poor in vegetable resources), Adrasta feared that her monopoly over metal would end and trapped the ambassador in a pit, taking advantage of his bestial appearance and inability to speak without his communicator to pass of the image of Erato as a mindless man-eating monster to which rebels would be fed (in reality, he was a mostly peaceful vegetarian).
As the Doctor managed to communicate with Erato and expose the scheme, Adrasta was overthrown and killed by her former servant known as the Huntsman, who declared the end of a dark age for Chloris and expressed interest in establishing commerce with the Tythonians. It's likely that their culture has evolved a great deal after that, possibly leading to the development of space traveling, but that's never been confirmed.
- Doctor Who season 17 - Creature from the Pit (1979)