"The Five Doctors" was a celebration of the first 20 years of the world's longest-running science fiction series "Doctor Who".
The episode was written by Hitchhiker's Guide to the Galaxy author Douglas Adams and, due to its incomplete nature, has gained mythic attention amongst devout Doctor Who fans.
Describing his return to the role, the 83-year-old actor said the Doctor "probably never left me". More recently, though, Baker played a mysterious character known as the Curator in 2013's "The Day of the Doctor".
The missing parts of the show that were omitted from filming in 1979 will be completed using animation, which Baker will voice, and the veteran actor has also filmed a live-action scene. On the 23rd, the BBC tweeted a video of Tom Baker wishing Doctor Who a happy birthday, where he called himself the "happiest" of Doctors.
The newly added scene involving Mr Baker was shot on the set of the 1979 Tardis and lines recorded for the animation are from the original script.
Despite attempts by new Doctor Who producer John Nathan-Turner to resume the episodes-scheduled to air January 19-Feb.
To mark the memorable episode, the BBC will opt to avoid its broadcast, but will instead make the special available as a digital download and also a DVD release.
It's exciting to see BBC give makeovers to lost or unfinished episodes of Doctor Who, which still unfortunately boasts huge gaps in the runs of the Second Doctor (Patrick Troughton).
Baker has played the role of the Doctor in audio plays and made his last on-screen appearance as the Time Lord in 1993 "Children in Need" special. "Doctor Who was more important than life to me - I used to dread the end of rehearsal... that's why I can't stay away from it. "Shada" was one of my favourite Doctor Who stories".