8 was a number.
Some species had eight legs, such as the Eight Legs (TV: Planet of the Spiders) and the Racnoss. (TV: The Runaway Bride)
The Visians were about eight feet tall. (TV: The Daleks' Master Plan) The humanoid natives of one planet were eight feet tall. (PROSE: Follow the Phantoms)
Jakra worms were eight feet long. (PROSE: Ghosts of India)
On Gallifrey, eight year old children were made to stand in front of the Untempered Schism for initiation. At age eight, the Gallifreyan who became known as the Master was implanted with the Drumming from the future of the Last Great Time War. (TV: The Sound of Drums, The End of Time)
The Fifth Doctor was told by Alistair Gordon Lethbridge-Stewart that he had worked with eight other incarnations of the Doctor by 1999, including four of his future incarnations. (PROSE: The King of Terror)
In 1978, Chad Boyle was eight years old when he almost killed Dorothy McShane, who was also eight. (PROSE: Timewyrm: Revelation)
Graffiti reading "TP8" in red was present in London on 25 December 2006. (TV: The Christmas Invasion)
The crew of the Elysium, by 17 July 1888, was eight men large. (PROSE: Pride of Mayfield Star Lines Beached in Devastating Storm)
In the language spoken by the people who accidentally flew a spaceship to the edge of the universe, the word for 8 was "Brate". (TV: Wild Blue Yonder [+]Loading...["Wild Blue Yonder (TV story)"])