Guests Aisling Bea and Adjani Salmon brought "comedy gold dust" to the set of Doctor Who while filming the New Year's Day special, according to star Jodie Whittaker.
Following the finale of Doctor Who: Flux, the Timelord and her friends will kickstart 2022 with a time loop action adventure special, set on New Year's Eve.
Eve of the Daleks will feature the 13th doctor, played by Whittaker, and Yasmin Khan. played by Mandip Gill, alongside Dan Lewis, who is portrayed by comedian John Bishop, being pursued by their biggest enemy, the Daleks.
Guest stars comedian Bea and actor Salmon join the festive episode, which will air on BBC One on New Year's Day. Bea's fellow Irish actor Pauline McLynn is also part of the cast.
Leading actress Whittaker, the first female Doctor, said: "I had met Aisling before - and had never met Adjani - so I knew how lovely Aisling was going to be and how hilarious she is.
"My first introduction to Adjani was when we did the read-through on Zoom and he was absolutely hilarious and I couldn't wait for his energy and Aisling's energy. They're so different and they complement each other so well.
"Because they're both from a world of comedy, which I'm not from or Mandip's not from - but obviously John is - it was like comedy gold dust just being on set with them. They were making us laugh the whole time."
Thirty-nine-year-old Whittaker announced in July she will be leaving the BBC sci-fi drama following the upcoming series and a trio of specials next year.
Bishop, 55, added: "The relationship between Aisling and Adjani is great - there are some ad-libs they dropped in, which they kept in, as they are great comic actors and both very funny.
"Aisling can flip her voices and characters and all that so there was loads of messing about and having a laugh."
Gill, 33, has said they all had "such fun" working together for the one-off episode. She said: "It was really fun to be working with Aisling and Adjani. They're very funny people.
"Aisling created these characters from my life and played them for me, just for me. It was like having a one-woman show every time we cut camera.
"There was a time where Jodie, Aisling and I really convinced ourselves that it would be a good idea to do a music video because there was a big silver gate and it reminded us of Girls Aloud's Sound of the Underground.
"We practised it, then we had to go to set, then we practised it again and in my head I really thought Adjani was actually our tour manager."
The New Year's Day episode is the first of three Doctor Who specials airing in 2022. The second special airs in Spring and Whittaker's final feature-length special will air in the autumn, as part of the BBC's Centenary celebration.
Dreaming Whilst Black star Salmon added: "The entire Doctor Who clique is like a family and a unit.
"It feels like a family working together and when we were in high-pressure environment it was still this synergy of everyone working and moving and getting it done.
"As a filmmaker, I'm watching it thinking 'I want this energy when I'm on set'."
Doctor Who: Eve of the Daleks will air on BBC One at 7:00pm on New Year's Day 2022.
Source: Press Association