Professor Stephen Hawking voices the Red Nose character Nose-it-All
Professor Hawking, 75, voices a Red Nose character – Nose-it-All – on a comic strip game, along with Warwick Davies, Hugh Dennis, Nick Grimshaw, Sir Lenny Henry, Harry Hill, Alex Jones, Katie Price and YouTuber Joe Sugg, which is now online.
He joked: "I'm a world-renowned scientist who has shaped our understanding of the universe and I am being asked to make snot jokes. I must really like this charity."
Ed Sheeran, Dawn French and Jennifer Saunders will be among those helping to present the night itself, along with Sir Lenny, Miranda Hart, comedian Romesh Ranganathan and Jonathan Ross.
Ed Sheeran will present the night along with others
I must really like this charity
Professor Stephen Hawking
Chart star Sheeran, 25, will be seen singing with children, many orphaned by the recent Ebola outbreak, on the streets of Liberia.
He said: "I'll never forget the kids I met on this trip. When we sang together, they were in such high spirits despite everything they'd been through.
"It was an incredibly eye-opening experience and I'm really proud to support Comic Relief and see what they are doing to help these children have a better future.
Comedy duo Vic and Bob will be causing chaos backstage
"The night will also feature sketches on BBC1 with TV character Mrs Brown from Mrs Brown's Boys and comedy duo Vic and Bob causing chaos backstage while bringing back classic characters the Stotts.
Chat show host Graham Norton will be seen interviewing guests on a "ludicrously long sofa", while an "international music mega star", yet to beannounced, will also take part in proceedings.
Graham Norton will be interviewing guests
Comic Relief 2015
Fri, March 13, 2015
Celebrities join in the Comic Relief red nose day campaigns.
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Russell Brand, Claudia Winkleman, Lenny Henry, Doc Brown, David Walliams, Stephen Fry, Idris Elba, Dawn French, Davina McCal for Comic Relief
Meanwhile, Reggie Yates, Katy Brand, Russell Kane, Hugh Dennis, David Baddiel and Michaela Coel drive across Kenya and Uganda to deliver supplies to Comic Relief funded projects.
• Red Nose Day – helping to change lives in the UK and Africa – takes place on March 24