One of Calvin's most-used aliases. Spiff travels through space in a small, round red spaceship that has a tendancy to be shot down over unexplored planets. (Calvin apparently has a model of this same design.)

Spiff, with his ray blaster set to "Deep Fry", often is the one to blame for flying elastics, rubber darts, or pine cones. The people around him become alien inhabitants of the current planet. Spiff self-narates the stories in superlative-filled language.

Spiff is a descendant of other characters Watterson drew. He first apppeared in Raumfahrer Rolf, a high school German project. During his college years, the character appeared as Spaceman Mort in an unfinished piece of work. Spaceman Spiff was the first strip he submitted to syndicates after college.