Brian Cox CBE
Known for: Playing villains in X-Men 2, The Bourne Supremacy and playing cinema's first Hannibal Lector in Manhunter as well as an extensive array of roles on stage and screen.
Voiced: The Ood Elder in David Tennant's final story The End of Time (2009).
This brainy Ood featured in one scene to mutter portents of doom at the Timelord and was never seen again. Cox will revisit the Whoniverse this November playing the programme's creator Sydney Newman in An Adventure in Time and Space, a special drama about the early days of the show written by Who and Sherlock stalwart Mark Gatiss.
Michael Sheen OBE
Known for: A dazzling array of work on stage and screen but principally playing Tony Blair in The Queen, David Frost in Frost/Nixon and some camp Vamps in the Twilight and Underworld sagas.
Voiced: House, the intergalactic, body-less entity that tried to eat the Tardis in Neil Gaiman's lauded The Doctor's Wife (2011).
The Welsh actor has long been linked to the title role (perhaps because of his superficial similarity to David Tennant coupled with unimaginative journalists) but his voicing of the sinister celestial entity, who tortures Rory and Amy, went largely unnoticed as the production team decided to modulate the famous actor's voice to the point where it was unrecognisable. Interestingly, Gaiman originally wrote House to be the classic Who villain The Great Intelligence, who would end up voiced by another famous actor...
Imelda Staunton OBE
Known for: Being Oscar nominated and BAFTA winning for Vera Drake but to the public at large she is reviled as the bigoted and spiteful Dolores Umbridge in the Harry Potter series.
Voiced: The Interface on Apalapucia in Tom McCrae's heartbreaking The Girl Who Waited (2011).
Staunton's brilliant skills don't necessarily translate very well to voicing a humourless computer interface. She's chirpy but unrecognisable as she aids a trapped Amy Pond in evading the accidentally deadly Handbots. I'd much rather see her be given a proper meaty role.
Mitchell and Webb
Known for: Their long list of work together, including the unparalleled Peep Show and one of the best sketch-comedies in this century, That Mitchell & Webb Look.
Voiced: Soloman's Robots in Dinosaurs on a Spaceship (2012).
Dinosaurs on a Spaceship already has a lot going on (Dinosaurs, imminent missile threat, Egyptian Empresses, Indian Space Agencies, Rory's dad) and then they go and throw one of Britain's best comedy duos into the roles of the devious Soloman's faithful robots. Having them voice the wonderfully inept machines is a fun little cameo; they are instantly recognisable as a mechanoid Jezz and Mark, bickering and chiding each other as they try to defeat The Doctor. Robert Webb is an avowed fan of the show and in previous interviews has expressed an interest becoming The Doctor:
"RW: I'd kill to be Doctor Who. Maybe they could make the Doctor two people? He has got two hearts after all.
DM: No. I think either of us would happily play the role - alone.
RW: Just to make sure the other one didn't get it.
DM: And then refuse to regenerate."
Sir Ian McKellen
Known for: If you're on the internet and you have no idea who that is, please reassess your priorities. A darling of the stage and screen, McKellen has made millions of fans in the last decade as Gandalf in The Lord of the Rings and Magneto in the X-Men franchise.
Voiced: The return of the Classic series villain, the Great Intelligence, in The Snowmen(2012)
McKellen's booming tones were a nice Christmas treat in last year's Special, playing the disembodied entity who uses Richard E. Grant to create a world of Snow monsters. While it was a nice cameo, McKellen was largely wasted as the character of the Great Intelligence was barely fleshed out; he was a maniacal Snowglobe whose motivations were not entirely clear and he was reduced to lampooning Game of Throne's famous catchphrase and being defeated by the tears of children. When the GI returned in The Name of the Doctor, he was played by Grant. McKellen is currently appearing on ITV's bawdy sitcom, Vicious which makes frequent light fun of his appearance in Doctor Who and, of course, he shares that stage with Sir Derek Jacobi, well known to fans as another of the Doctor's nemeses, The Master.