Myth
According to the Tenth Doctor, there were representations of a horned Beast in the myths and legends of a million planets across the universe. (TV: The Satan Pit)
The Shadow Architect believed that the Time Lords belonged in the "myths and whispers" of the higher species. (TV: The Stolen Earth) In a parallel universe, the Time Lords were a Skarosian myth, allegedly having tried to wipe out the early Kaled race, though it was one that Davros did not believe until he met the Eighth Doctor. (AUDIO: Palindrome
The Eleventh Doctor believed the Shakri to be a myth to keep young Gallifreyans in their place. (TV: The Power of Three)
By the year 100,000,000,000,000, shortly before the end of the universe, the Tenth Doctor, who identified as the last of the Time Lords, and his TARDIS were not recognised by the distant descendants of Earth humans who resided on Malcassairo. He said that he thought the end of the universe was a "bit humbling" after learning there were no legends and "not even a myth" about him. (TV: Utopia)
The research of human historians who studied the Daleks had led them to theorise that the accounts of the Daleks being descended from the blue-skinned Humanoid Daleks or that the Daleks hailed from Ameron were distorted myths about the Daleks, concocted by the subjugated races of the Dalek Empire to fit their noosphere. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)
The Thirteenth Doctor believed the Solitract to be a myth. (TV: It Takes You Away)