To mark the 90th anniversary of A.A Milne’s first Winnie-the-Pooh book, a new face will join the Hundred Acre Wood residents.

Piglet, Eeyore, Tigger and the rest of Pooh’s animal friends will be accompanied by a new pal, Penguin, in an official sequel, Winnie-the-Pooh, The Best Bear in All the World.

The characters in the series were inspired by Milne’s son – the real-life Christopher Robin’s – stuffed toys.

But for some reason the Antarctic bird was left out.

Pooh’s long-forgotten friend wasn’t discovered until the sequel’s author, Brian Sibley, saw a photo of Milne and his son playing with a stuffed penguin and the teddy bear, which became Winnie-the-Pooh.

The bear, like all the other toys that inspired the series’ beloved characters, was reportedly bought by Christopher’s mother, Daphne Milne.

New 'Penguin' character introduced to Winnie-the-Pooh, inspired by A A Milne photograph: https://t.co/Be0yK0JJx5 pic.twitter.com/qTtV7jPJ3Y

— The Bookseller (@thebookseller) September 19, 2016

Sibley will introduce Penguin in a story titled Winter: in which Penguin arrives.

“I remembered seeing a photograph of father and son playing on the nursery floor with Winnie-the-Pooh and a penguin,” Sibley told Britain’s The Telegraph newspaper.

“The thought of Pooh encountering a penguin seemed no more outlandish than his 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.”

Penguin will be the first new character added to the iconic story since Milne’s death in 1956.

Sibley’s book will be the second authorised sequel since Milne’s death, after David Benedictus’ Return to the Hundred Acre Wood of 2009.

Winnie-the Pooh, The Best Bear in All the World will be available in Australia on October 1.