Artist, cartoonist and author of the hit comic strip "Calvin and Hobbes" makes a rare appearance in another comic strip after years of living in seclusion.

Bill Watterson, cartoonist of "Calvin and Hobbes," drew some cartoons with a fellow artist and cartoonist Stephan Pastis in the acclaimed comic strip "Pearls Before Swine." Watterson made his debut on June 4 to 6. Some fans had no idea, while others were just curious, but Pastis most of all, was excited, nervous, and shocked to be working with his idol.

Watterson created the popular "Calvin and Hobbes" comic back in 1985, but 10 years later he ended the cartoon.

Pastis has described working with Watterson as "editing the pope," and that it was "Like telling Michelangelo: David's hands are too big," the New York Daily News reported.

In case anyone didn't know, there was proof in black and white, and in many newspapers and online, in full color. It was "Pearls Before Swine's" characters Rat and Pig, sharing panels with the work of legendary "Calvin and Hobbes" Watterson, the creator of the mischievous boy, his stuffed tiger, and the never-ending space and time-defying alter egos, CNN reported.

Watterson made his debut in the form of a little girl named Libby, a second grader with a natural talent for drawing, who took control of the comic. It was as Libby that Watterson had dived into familiar imagination where a crocodile eats Pastis; then, a pig and mouse debate the fact that a new artist will change everything they do and say, while a giant robot attacks, the New York Daily News reported.

Pastis and Watterson got in touch on April 11. It all started when Pastis completed a strip that inaccurately portrayed himself pretending to be the author of "Calvin and Hobbes" so that he could get a woman to sleep with him. Prior to that, Pastis was told by a mutual friend, The Washington Post cartoonist Nick Galifianakis, that Watterson had been wanting to get in touch.

Then Watterson and Pastis finally exchanged e-mails, and Watterson was the one who suggested doing something together.

Apparently, Watterson is a longtime "Pearls Before Swine" fan. Watterson told The Washington Post that several years ago, when Pastis had done a strip in which he mocked his own drawing ability and mentioned his strip in comparison, Watterson thought it might be funny for him to "ghost" "Pearls Before Swine" for a little while.

Watterson is known to be a very reclusive and private person. To date, there is only one known picture of him in in existence. Pastis says of Watterson's craft that he is "one of the finest draftsmen to ever pick up a pencil."

And Pastis also learned that Watterson is the least tech-savvy person that he knows; at first he wanted to exchange work via actual hand-delivered mail but Pastis convinced him not to because he feared that Watterson's drawings would somehow get out there. Pastis explained that Watterson could not set the scanner correctly to get rid of the pencil lines, and that he had trouble sending attachments, among others.

Watterson's work with Pastis speaks volumes.