A Reptilian humanoid species. They developed an advanced space faring civilisation with a high aesthetic sense and some mild warlike tendencies. Although they can breathe oxygen, they cannot survive long without breathing soliton gas, which is highly combustible when combined with it. They are known to employ androids and to prefer forced labour (mainly in the tinclavic mines of the planet Raaga) to the death penalty.
Source: Doctor Who, The Visitation (Eric Saward)