Ninth Doctor 1 (The Tomorrow Windows)

A possible ninth incarnation of the Doctor was seen by the Eighth Doctor in the Tomorrow Window. He was stockily built and wore a crushed velvet suit and eyeliner; the Eighth Doctor described his pose as "star[ing] arrogantly into the distance". (PROSE: The Tomorrow Windows)

Behind the scenes
According to Jonathan Morris, this incarnation's appearance was based on actor , who was a rumoured actor for the Ninth Doctor in 2003 before the reveal of Christopher Eccleston. The rumour was prolific enough that Fourth Doctor actor Tom Baker openly spoke in favour of Izzard's hypothetical casting.

Izzard is genderfluid, and since 2019 has only used she/her pronouns. This detail was obviously not considered for The Gallifrey Chronicles, which was released in 2005.