Spaceman Spiff

Spaceman Spiff is Calvin's Space-Explorer-Extraordinaire alter ego. Spaceman Spiff can be traced back to a comic strip Watterson drew for a high school German class, called Raumfahrer Rolf. It was a two-page comic in which the protagonist got eaten by a monster at the end, but it was written in some sort of German, and that was what counted. The character was reworked calling him "Spaceman Mort", but the strip was conceived as a fairly elaborate, continuing project and that didn’t seem like the best use of his academic time, so it was never published. A year or so after college, the newly christianed Spaceman Spiff was Watterson's first strip submission to newspaper syndicates. Spiff was a diminutive loudmouth, not unlike Calvin, albeit with a Chaplin mustache, flying goggles, and a cigar. He had a dimwitted assistant named Fargle, and they roamed through space in a dirigible. The syndicates rejected it. Years later, Calvin and Hobbes were created, Watterson finally had the opportunity to bring Spiff back.

Although the Spiff strips are limited in narrative potential, but Watterson feels that they’re so much fun to draw. The planets and monsters offer great visual possibilities, especially in the Sunday strips. Most of the alien landscapes come from the canyons and deserts of South Utah, a place more weird and spectacular than anything. 

Stupendous Man

Stupendous Man is Calvin's superhero alter ego. He fights the tyrany of such villians as Babysitter-Girl and the Evil-Bedtime-Lady. He appears mostly in multi-strips.

Tracer Bullet

Tracer Bullet is Calvin's private eye alter-ego. Often than not, he attempts to solve the mystery of the broken vase and the case of the geometry problem. Tracer Bullet seldom appears in Calvin and Hobbes.