Logopolis Watcher

The very first regeneration in 1966's The Tenth Planet (c) BBC Studios Doctor Who William Hartnell

Logopolis’ mournful air includes the Doctor being literally haunted by his future self. The Doctor, Nyssa, and Adric discuss something, while in the middle distance behind them, a half-formed figure all in white watches them (c) BBC Studios

First Doctor regeneration
Regenerations Round One