The Thoi'han were an advanced reptilian species native to the planet Thoih.
They were famous for developing advanced space travel technology known as the Infinity Gates. This technology allowed them to travel between their various colonies.
They once fought against another race known as the Inusannon. In the end, the Infinity Gates were destroyed and their empire was fractured. While many population wiped each other out, at least two populations on the current Terran Federation colonies of Chasca and Fehl Prime actually degenerated into simple beasts.