The historian and broadcaster will appear on the kids' programme on Monday 10th January. Announcing the exciting news, BBC said: "Celebrate @BBC’s The Green Planet with a special @heyduggee voiced by Sir David Attenborough."
The episode is available to stream on iPlayer now.
CBeebies had teased David's appearance last week week, taking to Twitter to explain: "#HeyDuggee's NEW special episode will feature a very important guest... Tune in to CBeebies on 10th Jan then stream on iPlayer Tell us your guess!"
They then listed a series of clues to help viewers guess - and plenty of people immediately assumed it would be Sir David!
The three clues included: "They know about plants and animals from all over the world. They have travelled to every continent in the world. They have a very memorable voice."
And after CBeebies had posted the clues, one person commented: "DAVID ATTENBOROUGH!"
While another said: "OMG IT'S DAVID ATTENBOROUGH!!!"
And a third added: "Oh my gosh.....YES!"
One posted a picture of Sir David and wrote: "Oh my goodness!! Best guest ever?!"
We cannot wait to see this!
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