The Fourth Doctor popped up at the end of 'The Day of the Doctor', playing the enigmatic role of The Curator, directing Matt Smith's Doctor towards his next adventure.
> Doctor Who 50th: Digital Spy's 'The Day of the Doctor' review
Baker, who played the iconic character between 1974 and 1981, was interviewed for BBC Three's After Party show following the transmission of the 50th anniversary, and spoke about the significance of the sci-fi series in his life.
"It's been my entire existence. I'm delighted to be celebrating it," Baker said.
"It was the happiest time of my whole life."
Commenting on the show's fans, he added: "They give me the credit for making Saturday more fun than it really was, in between the football, Basil Brush and Bruce Forsyth. I was right up there with all those legends and I'm grateful."
'The Day of The Doctor' featured David Tennant and John Hurt teaming up with Matt Smith, with Jenna Coleman and Billie Piper in supporting roles.
Digital Spy embarks on a journey of discovery to mark 50 years of Doctor Who in a new short film, Doctor Who: 50 Years of a TV Icon. Watch below: