Prince William reveals Charlotte's adorable obsession

We may think of Princess Charlotte as a tiny royal, but Prince William has proven that she's just like any four-year-old girl by revealing her latest obsession.

William took part in an art therapy session while visiting Harcombe House in Devon on Monday, where he was marking Emergency Services Day.

There he spotted a collection of artworks made by a local firefighter's children including one of a unicorn made with colourful balls.

With three children of his own it's only natural that William took an interest in the artworks, but the unicorn in particular caught his eye.

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"My daughter loves unicorns," he revealed to the group taking part in the art therapy session.

"Loves them. Very cool."

Charlotte has already showed off her fondness for unicorns, making her 'big school' debut at Thomas' Battersea school last week with an adorable unicorn keychain attached to her bag.

The sequined pink keyring added a girly touch to her school backpack and served as a sweet reminder that Charlotte really is just like other children her age.

She was also spotted earlier this year carrying a cute unicorn purse at the King Power Royal Charity Polo Day, where she was seen kicking around a soccer ball with big brother Prince George.

Charlotte and George were later spotted mucking around in the boot of the family car while Kate sat on the grass nearby with Prince Louis, looking just like any other young family.

It's moments like these that make it so easy to forget Charlotte and her brothers will one day be senior royals tasked with overseeing the British monarchy.

But it seems that for now they're happy to enjoy just being kids.