Calvin and Hobbes creator Bill Watterson makes surprise return

The legendary cartoonist guest-drew a syndicated strip alongside Pearls Before Swine creator Stephan Pastis

Mr Watterson had not drawn for almost 20 years (Juliana Luz/Flickr CC)

Reclusive cartoonist Bill Watterson has emerged from nearly two decades in retirement to guest-draw a syndicated comic strip that runs in 750 newspapers globally.

The Calvin and Hobbes creator collaborated with fellow cartoonist Stephan Pastis, creator of Pearls Before Swine, on three strips that were published throughout last week.

But it was not until Friday that Mr Pastis revealed the man behind the drawings.

Writing on his blog, Mr Pastis explained that he had written to Mr Watterson to express his admiration. Not expecting a response, he was shocked when the cartoon titan not only replied, but also said that he had an idea that he wanted to run past Mr Pastis.

Together the pair conceived a series of comic strips in which Mr Watterson would appear under the guise of a 12-year-old girl called Libby, who would mock Mr Pastis' drawings - in reference to the self-deprecation that characterises his work - before going on to produce her own cartoons.

Mr Pastis described working with Mr Watterson as "the highlight of my career".

Calvin and Hobbes was a daily comic strip that was syndicated from November 1985 until December 1995. It featured a six-year-old boy and his sardonic stuffed tiger and appeared in over 2,400 newspapers worldwide. But the strip came to an end after Mr Watterson announced that he had done as much as he could in the medium.

And the JD Salinger of cartoons retained his air of mystery while working with Mr Pastis: the whole project was conducted by email and the pair never even swapped phone numbers.