Tarwildbaning

 was a Euterpian. He was part of a five member recon team from the Euterpian mothership that landed on Earth around 40,000 BC. They planned to refuel the mothership from Earth's magnetic core, but before that happened, the mothership was destroyed by solar flares. The recon team (Atimkos, Godwanna, Thorsuun, Udentkista, and Tarwildbaning) were the only survivors. Their plans to destroy Earth in 1994 were defeated by the Second Doctor.

When they discover their homeworld no longer exists, Udentkista and Tarwildbaning decide they like their life on Earth, and help to stop their fellow Euterpians' plans. (PROSE: Invasion of the Cat-People)