Tracer Bullet

Tracer Bullet is a fictional detective from Bill Watterson's Calvin and Hobbes comic strip. Like Calvin's other major alter egos, Stupendous Man and Spaceman Spiff, he appears when Calvin finds himself in a situation he can't handle, solving simple dilemmas like math problems and broken objects. He is a detective styled after film noir and detective fiction stereotypes; consequently, he wears a trench coat and fedora. He resembles Calvin somewhat, though the high-contrast art style Watterson uses in the Tracer Bullet strips makes Bullet's features harder to see and obscures the similarity.

The name Tracer Bullet is a pun on tracer ammunition, a type of bullet used in machine guns to let the operator see where they are hitting.