Stars from Strictly, Star Wars, Doctor Who and EastEnders are lending a hand to Children In Need to help raise funds in this year's charity BBC TV appeal.
The five-hour telethon also features England football players, a celebrity edition of music quiz The Hit List and songs by Louis Tomlinson and Westlife.
They are all hoping viewers will donate to Children In Need, which supports 3,000 local charities and projects.
Last year, £50.6m was raised on the appeal night.
Children in Need is the BBC's official UK charity and raises money for disadvantaged young people around the country, such as those experiencing poverty, with disabilities, or victims of abuse or neglect.
This year, comedian Tom Allen joins a presenting line-up that also includes Graham Norton, Tess Daly, Mel Giedroyc, Ade Adepitan and Marvin and Rochelle Humes.
EastEnders actors Ricky Champ (who plays Stuart Highway), Louisa Lytton (Ruby Allen), Maisie Smith (Tiffany Butcher) and Rudolph Walker (Patrick Trueman) swap Albert Square for the Strictly Come Dancing ballroom for the night.
Star Wars actors Daisy Ridley and John Boyega challenge YouTuber Colin Furze to build a real working landspeeder [vehicle that hovers], helped by young people from Children In Need projects.
Doctor Who's Jodie Whittaker also makes an appearance, and Norton gives three children the chance to be on his chat show sofa - and the power to tip joke-telling celebrities out of his famous big red chair.
Meanwhile, there are special versions of Mock The Week, Crackerjack and Dragon's Den, along with performances from Michael Ball and Alfie Boe, plus the casts of Big, The Tina Turner Musical and Circus 1903.
England footballers Harry Kane, Marcus Rashford and Raheem Sterling have been filmed surprising children from the England Amputee Football Association.
A special edition of BBC One's The Hit List features pop stars including rapper Wretch 32, ex-JLS singer JB Gill, Heidi Range from the Sugababes, Girls Aloud's Nadine Coyle, Liberty X star Michelle Heaton and Blue's Antony Costa.
TV personality Rylan Clark-Neal has already raised more than £1m for the cause with his 24-hour karaoke marathon on BBC Radio 2.
Children in Need is on BBC One at 19:30 GMT on 15 November