Viewers will see the first footage from this year's Doctor Who Christmas Special which sees the return of Matt Smith along with guest stars Claire Skinner, Alexander Armstrong and Bill Bailey. The title of the much-anticipated episode will also be revealed.
Earlier this week, Matt Smith recorded a Doctor Who sketch at the BBC Television Centre. It is directed by Richard Senior and written by Steven Moffat. The scene, to be shown tomorrow, will see the Doctor auctioning off his iconic costume.
Matt Smith said: "I hope people donate generously for BBC Children in Need because it's a wonderful cause- and we've got to beat last year's total. I saw Terry Wogan on TV the other night, and thought come on! Let's make more money! So hopefully we can raise a good amount.
"I'd say the tweed jacket or the bow-tie are the most iconic - although the boots are my personal favourite."
The highest bidder will receive Matt Smith's costume - consisting of a Tweed jacket, Shirt, Black jeans, Black boots, Braces, Bow-tie and Watch - as seen earlier this year in The Doctor's Wife. A copy of Steven Moffat's script, signed by Matt Smith, will also be going up for auction.
It all kicks off tonight at 7.30pm on BBC One.
The Children in Need appeal raises money to help disadvantaged children around the UK.
To donate, visit: http://www.bbc.co.uk/pudsey/donate/