The Mr Men get a makeover - cherished characters updated for new children's TV series

The instantly recognisable characters have delighted children for decades. But the producers of a new Mr Men TV series could not resist the urge to 'update' them.

The simple line drawings created almost 40 years ago by Roger Hargreaves have been altered because, the makers say, 'children's expectations of cartoons have changed'.

Mr Strong – previously square and fond of wearing a trilby – has become a triangle with bulging biceps and a weightlifter's belt.

More follows...

Click here to play our exclusive interactive Little Miss Scary computer game!

Little Miss Naughty, meanwhile, who was never adorned by anything more than a flamboyant bow, has sprouted a Vicky Pollard-style mop of hair.

The new Mr Men Show, which will be broadcast on Channel Five in the New Year, will even include some Mr Men switching sex to become Little Misses.

And instead of inhabiting their own worlds, the characters will live in the fictional land of Dillydale. The show will be screened as short comedy sketches, pairing Mr Happy with Little Miss Grumpy, and Mr Bump with Little Miss Helpful.

John Collins, from Chorion, the company behind the new series, said modern children 'need to be able to tell, for example, that Mr Strong is strong just by looking at him – so now he has muscles'. But he insisted that the firm had no intention of making the characters 'too modern' by equipping them with gadgets such as iPods.

When the BBC started making the original Mr Men series in 1974, it chose Dad's Army star Arthur Lowe to do the voices.

The new makers will use several voices and are currently auditioning actors with regional accents from Scotland, Birmingham, London and Yorkshire to decide which best fits the likes of Mr Bump, Mr Bounce, Mr Tidy and Mr Messy.

A new range of merchandise will include soft toys, computer software and books. The show is expected to be sold around the world and a deal has already been secured in America.

Chorion, run by Labour peer Lord Alli, bought the rights to the Mr Men in 2004 for £28million from the Hargreaves family. The 48 Mr Men and 35 Little Miss books have been published in 22 languages, with about 100million copies sold in 30 countries.

When Mr Hargreaves died in 1988, his son Adam took over development of the characters. Earlier this month Paddington Bear's creator Michael Bond was accused of 'selling out' by letting Paddington ditch his beloved marmalade in favour of Marmite in a TV advert.

But Adam Hargreaves said: 'I'm terribly excited about the new show. I think my Dad would have been thrilled.'

Click here to play our exclusive interactive Little Miss Scary computer game!