Christopher Lloyd to guest star in The Big Bang Theory

Christopher Lloyd will guest star in ‘The Big Bang Theory’.

The 78-year-old actor – who is best known for his iconic role as Doctor Emmett Brown in the ‘Back to the Future’ trilogy – is set to make a guest appearance on the American sitcom.

Christopher’s role and storyline is as yet unknown, but an executive producer for the series has promised fans will "really enjoy" the star’s part.

They said in a statement released on Wednesday (09.11.16): "We’re so excited to be working with Christopher Lloyd, and think we’ve created a fun part that fans will really enjoy."

‘The Big Bang Theory’ is based around four intellectual and geeky friends – Leonard Hofstadter (Johnny Galecki), Sheldon Cooper (Jim Parsons), Howard Wolowitz (Simon Helberg), and Rajesh Koothrappali (Kunal Nayyar) – and their less intellectual neighbour Penny (Kaley Cuoco).

The new casting comes after CBS – who air the science-centric show – recently announced they were planning a spin-off series that focuses on the early life of Sheldon Cooper. The series is in early development, but it is expected to not feature any of the current cast in on-screen roles, however Jim Parsons has been tipped to executive produce.

‘The Big Bang Theory’ has been named as TV’s top comedy, and is currently in its 10th season. The show has not yet been renewed for another season, but it is expected that another pickup will come shortly with highly-paid deals for the main cast.

For Christopher, the role comes after he recently signed up to appear in Syfy’s third season of ’12 Monkeys’.

The episode of ‘The Big Bang Theory’ featuring the ‘Taxi’ star will air on CBS at 8pm on December 1.