David Bradley had a "great time" starring as the original Time Lord in the "Doctor Who" Christmas special.
The 75-year-old actor will portray the First Doctor - originally portrayed by William Hartnell - in the festive episode "Twice Upon a Time" this year when Peter Capaldi's Twelfth incarnation regenerates into Jodie Whittaker.
Bradley first appeared as the First Doctor brought back to life on the screen by the actor in making of "Doctor Who" drama "An Adventure in Space and Time" back in 2012, and admitted he loved the "erratic" character.
Speaking to The Daily Telegraph newspaper, he said: "I had such a great time doing the first one and I felt I'd steeped myself in it. The fact that the original Doctor was a bit erratic made him quite appealing to me. Hartnell was a very complex man.
"They started to cast him as these bullet-headed authority figures and he felt he'd got trapped."
New showrunner Chris Chibnall has bravely taken the decision to make Whittaker the first woman to play the time traveller.
David - who starred with Jodie on Chris" crime drama "Broadchurch" - said he was "absolutely delighted" when he heard the 35-year-old actress had bagged the iconic character.
He said: "Absolutely delighted. Jodie's got such an emotional range.
"Anybody who's hung out with her knows she's just got a wicked sense of humour and she's subversive and funny and really nice with it.
"I think she'll be great."
David also believes Chris is the perfect person to replace outgoing showrunner Steven Moffat because he is such a talented scriptwriter and has lots of history with the BBC sci-fi series.
"Twice Upon a Time" will focus on the end of the First Doctor's era and will feature the Twelfth Time Lord having to convince the original that he has to accept his regeneration.
The hour-long special will also be last appearance of Pearl Mackie as companion Bill Potts before Jodie joins with her new TARDIS team; Bradley Walsh as Graham, Tosin Cole as Ryan and Mandip Gill as Yasmin.