James Bond stars Daniel Craig and Sir Roger Moore will appear in a film for this year's Comic Relief appeal that aims to top 2013's total of £100m.
David Walliams co-wrote the sketch which also features 007 director Sam Mendes and Skyfall actors Rory Kinnear and Ben Whishaw.
Walliams' Little Britain character Lou will appear in another film alongside scientist Professor Stephen Hawking.
And TV host Dermot O'Leary is currently raising money by dancing for 24 hours.
The X Factor presenter started gyrating at 19:00 on Thursday evening and had attracted donations of more than £100,000 by 09:45 on Friday, where he was joined by celebrities including comedian John Bishop.
Speaking 16 hours into his danceathon, O'Leary revealed to Radio 2 presenter Ken Bruce that he had swapped energy drinks for "tea with a lot of sugar".
"After two of them, you just can't stand the taste any more," he said.
If O'Leary's energy was flagging, he was revitalised by the sight of his hero Sir Terry Wogan and a group of Morris dancers.
He then joined the troupe, who accompanied Sir Terry as he sang the Floral Dance.
Comedy characters revived
Friday's fundraiser will be broadcast on BBC One, coming for the first time from the historic London Palladium.
Music stars John Legend - who won an Oscar last month - and Grammy-winner Sam Smith will perform a duet of Smith's song Lay Me Down.
A band of comedians including Jack Dee and Vic Reeves will also stage a special "tribute" to One Direction. Other musical performers include Ella Henderson and singer-songwriter Labrinth.
A host of the UK's best loved comic creations are also being revived for the charity which was founded by Lenny Henry and Richard Curtis 30 years ago. The first red nose day was held in 1988.
Dawn French returns as the Vicar of Dibley with Geraldine campaigning for the role of the next female Bishop.
Rowan Atkinson's beloved Mr Bean will return to Red Nose Day for the first time in eight years, joined by Ben Miller and Rebecca Front.
The classic Yorkshiremen sketch, famously performed by Monty Python, is to be recreated with a modern edge by John Bishop, Eddie Izzard, Davina McCall and David Walliams.
And a special edition of The Great British Bake Off: An Extra Slice, presented by Jo Brand with Frank Skinner and Mary Berry, will see four Star Bakers from The Great Comic Relief Bake Off series compete against each other.
A series of short films will also remind viewers of the serious side of Comic Relief's work, with appeal films presented by Peter Capaldi, Olivia Colman, Idris Elba and Lenny Henry
The live shows starts on BBC One at 19:00.