The Transient Beings were mentioned by the Fifth Doctor as having the necessary time sensitivity for the operation of the Crystal Bucephalus, along with the Legions, Tharils, Eternals, and Chronovores. (PROSE: The Crystal Bucephalus)

The Sixth Doctor later described the Great Old Ones as "transient beings". (PROSE: Millennial Rites)

Community content is available under CC-BY-SA unless otherwise noted.