Lenny Henry (in-universe)

Lenny Henry was a presenter for Comic Relief.

While getting ready in his dressing room he began feeling ill. He then started to regenerate, the then through unexplained reasons turned into the Fourteenth Doctor. (TV: Comic Relief 2023)

The Thirteenth Doctor had similarly regenerated into someone else when she turned into the Spy Master. Like Henry, the Thirteenth Doctor too would regenerate into the Fourteenth Doctor. (TV: The Power of the Doctor)

Behind the scenes

 * It is unconfirmed if the Seventh Doctor from untitled is the same character as in-universe Henry.