Tracer Bullet is a hard-boiled private investigator styled after film noir and detectivefiction stereotypes, especially Sam Spade of The Maltese Falcon (novel), who spouts incisive metaphors and wears a trench coat and fedora. He resembles Calvin, though the Frank Miller-like high-contrast art style Watterson uses in the Tracer Bullet strips obscures Bullet’s features. Watterson considered this style dramatic but regarded it as time-consuming, so he drew few Tracer Bullet strips. There have been only three strip sequences that involved Tracer Bullet. Tracer Bullet owns at least 3 guns, a .38 revolver, a .44 magnum and a .45 handgun.
Watterson first used Tracer Bullet in a story where Calvin has Hobbes cut his hair because, “the barber never cuts it the way [he likes],” and ends up bald. This story turned out to be one of Watterson’s favorites: the sight of Calvin’s haircut was one of the few times his own work made him laugh aloud, and Calvin’s use of a fedora to cover his head led to the introduction of Tracer
Bullet. Watterson would later lament, “Wish that I could write like this more often” (Tenth Anniversary Book).Tracer Bullet only appeared twice more. In his second appearance, Calvin has to solve a problem on a math test and imagines the process as Tracer Bullet. He last appeared in a story wherein Calvin and Hobbes break a lamp during a football game.