"It is a cattle prod. It hurts a little less than a branding iron."

- Calvin and his doctor, who shows an example of his sense of humor.

Calvin's doctor is a pediatrician with a wry sense of humor. As with most adults, Calvin isn't too fond of his doctor, and he is one of the few characters who terrifies Calvin. In one incident Calvin is out of control and the doctor asks for the anaesthesiologist.

Despite his wry approach, he has sometimes been known to lose his temper with Calvin, at one point threatening "Kid, don't make me recite the Hippocratic Oath".