The star revealed the exciting news on Instagram, while revealing details about the plot on Instagram stories.
The synopsis reads: "1940. Britain is at war with Nazi Germany. Eleven-year-old Eric spends his days at the place that makes him most happy: London Zoo. And there’s one animal in particular he loves: Gertrude the gorilla.
WATCH: David Walliams opens up about son Alfred
"With bombs falling all over London, Eric must rescue Gertrude. Together with his Uncle Sid, a keeper at the zoo, the three go on the run. But while hiding out at the seaside they uncover a top-secret Nazi plot."
He also revealed that Waterstones had a special price for the book. Sharing a snap of his new novel, he wrote: "To celebrate bookshops all over the country reopening, @Waterstones have extended their HALF PRICE offer for CODE NAME BANANAS!"
Code Name Banana by David Walliams, £7,49, Waterstones
David has written 15 children's books now, including The Boy in the Dress and Gangsta Granny, and has sold over 37 millions copies of his books worldwide, impressive!
While David will be presenting It'll Be Alright on the Night on Saturday, we're particularly looking forward to the Christmas special on 19 December, It'll be Alright on the Night at Christmas.
In the episode, David will review this year's greatest TV blunders, featuring the UK's most famous faces from World Leaders and members of the Royal Family.
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