Extras are minor characters in Calvin and Hobbes that have no dialogue and are not mentioned or named by other characters. They are usually seen in the background and rarely appear more than once. They include:
- 514 1986: Waiter in restaurant.
- 7/6 1986: Beachgoers.
- 7/24 of 7/21 through 7/26 1986 story arc: Children in Rosalyn's swimming lessons.
- 8/7 1987: Man in restaurant.
- 2/3 1989: Other waiter in restaurant.
- 1/26/1990: The extra duplicate.
Metafictional extras
Metafictional extras appear in fantasies of Calvin's. They are usually seen in the background and rarely appear more than once. They include:
- 7/20 1986: Pedestrians fleeing from Calvin the Giant.
- 12/11 1987: Lynch mob for Calvin the Criminal.
- 2/5 1989: Pedestrians and motorists fleeing from a possible Tyrannosaurus.