Image copyright Pooh Properties Image caption Illustrator Mark Burgess took inspiration from the original EH Shepard drawings when creating Penguin for the new books

Four new adventures have been published to mark the 90th anniversary of the first Winnie-the-Pooh book, along with the introduction of a new character.

Penguin makes his grand entrance in the book Winter: In which Penguin arrives in the Forest, written by Brian Sibley.

The character is based on a photograph of Pooh author AA Milne and his son Christopher playing with a penguin.

Winnie-the-Pooh was first published on 14 October 1926, and went on to achieve worldwide popularity.

Introducing a new character to the world of Winnie-the-Pooh is nothing new.

Although now considered very much a part of the Hundred Acre Wood story, the character of Tigger was not seen until The House at Pooh Corner (1928), the second of AA Milne's books about "the bear with very little brain".

And by introducing Penguin, Sibley has rekindled a friendship which first began in Christopher Milne's (aka Christopher Robin) nursery more than 90 years ago.

Sibley said: "While pondering what other toys Christopher Robin might have owned, but which were never written about, I remembered seeing a photograph of father and son playing on the nursery floor with Winnie-the-Pooh and a penguin!"

Image copyright Pooh Properties Image caption Penguin, pictured here in the nursery with Pooh, A.A. Milne and Christopher (Robin) Milne, is welcomed to the Hundred Acre Wood in a new series of books to celebrate the 90th anniversary of Winnie-the-Pooh.

"The thought of Pooh encountering a penguin seemed no more outlandish than him meeting a kangaroo and a tiger in a Sussex wood, so I started thinking about what might have happened if, on a rather snowy day, Penguin had found his way to Pooh Corner," said Sibley.

'Fresh inspiration'

By taking inspiration from the real-life childhood nursery toys of Christopher Milne (aka Christopher Robin) Sibley is in good company.

Many of the animals featured in Winnie-the-Pooh and The House at Pooh Corner, including Tigger, Eeyore Kanga, Roo and the eponymous bear himself, were bought from the Harrods toy store in London by Daphne Milne, Christopher's mother.

Some were bought as gifts, whilst the others were, in the words of Milne, "carefully chosen with the idea of not only giving pleasure to the reader, but also fresh inspiration to the chronicler of their adventures."

And Harrods archivist Sebastian Wormell believes the penguin pictured in the photograph could also have come from the Knightsbridge store.

He said: "In the early years of the 20th Century, toy penguins soared in popularity as the exploits of Antarctic explorers such as Shackleton and Scott fascinated the public.

"At that time it was all about the race to the South Pole and it's interesting to see how the range of toys and their popularity reflected the big news stories of the day."

"Toy penguins can be found in Harrods catalogues as far back as 1912, with a toy called Lieutenant Shackleton's Penguin.

"But after looking at the photograph and based on our thoughts on the date it was taken we believe that the toy pictured could be Squeak, which came from our 1922 catalogue.

"It's exciting to think that a new Harrods toy could be joining Winnie-the-Pooh's gang after all this time."

Image copyright Harrods Archive Image caption Squeak the penguin featured in the 1922 Christmas edition of the Harrods News

When asked why it has taken until now for Penguin to feature in the Pooh bear stories, Mr Wormell suggests Squeak's links with another penguin of the era could have influenced Milne's decision not to include him in the original Hundred Acre Wood line-up.

He said: "Squeak was part of a set of merchandise, which also included a dog and a rabbit, connected with a popular cartoon of the time, Pip, Squeak and Wilfred, so he was already a well-known penguin.

"And although Milne's characterisation of his penguin in the stories would likely have been very different to that of the cartoon's, it is probably why he didn't include one in the original stories.

"But time has moved on and the connection with the old cartoon is not well-known which is why I think now is such a good time to bring this penguin into the story."

And Mr Wormell praised the way Sibley has introduced the new character.

He said: "Brian Sibley has created a character that fits in well with the other characters we know. But with Penguin he also brings a new dimension to the story."