Matt Lucas will have a major role in the 'Doctor Who' Christmas special.
Matt Lucas
The upcoming festive episode will see Peter Capaldi's Time Lord without a companion as Pearl Mackie won't make her debut until 2017, and so the 42-year-old comic's alter ego, Nardole - River Song's former assistant who was featured in last year's seasonal saga with his head on a robot - will step into the position.
A source told RadioTimes.com: "The Doctor won't have a temporary companion this Christmas and essentially that space will be taken by Nardole.
"He's not a companion as such but it's not as if he doesn't play a similar role."
It was previously confirmed that Nardole would appear in the upcoming season 10 of the show - which begins in April - but his presence in the as-yet untitled Christmas special hadn't been revealed.
Sources also told the website 'War of the Worlds' actor Justin Chatwin will play a "superhero character" in the Christmas special.
The 33-year-old Canadian actor is expected to portray a "brash figure" with an American accent.
Actor and writer Mark Gatiss recently admitted the Christmas special made him cry and he thinks it is showrunner Steven Moffat's best work to date.
He said: "I think the Christmas special... which is the only one this year...I think is one of Steve's best ever scripts, absolutely beautiful. It made me cry."
But Mark stopped short of revealing anything that's in store for the Doctor in both the Christmas episode or season 10.
He simply said: "What can you expect? The Doctor is in it. It's great!"
Tagged in Matt Lucas Peter Capaldi