David Walliams is to spend 24-hours hosting a quiz show for Comic Relief.
The British funnyman - who famously swam the English Channel in 2006 and led a team of celebrity cyclists on a non-stop Land's End to John O Groats relay to raise money for the 2010 Sport Relief campaign - will both present and take part in comedy quiz show '24 Hour Panel People'.
Taking place on March 18, the live online programme will be broadcast on BBC Three as five 30 minute episodes in the run-up to the annual fundraising event.
David said: "This is an amazing challenge. I just hope I don't fall asleep or burst into tears."
Other comics taking part in the show - which will film on March 5 and 6 - include Sean Lock, Jason Manford and Leigh Francis.
The programme will incorporate elements of other popular comedy quiz shows, including '8 Out Of 10 Cats', 'Have I Got News For You', 'Celebrity Juice', 'They Think It's All Over', and 'Never Mind The Buzzcocks', as well as games specially-created for '24 Hour Panel People'.
Proceeds from '24 Hour Panel People' will go to Comic Relief, which tackles poverty in the UK and Africa.