- Onion (Calvin)
- Fat (Susie)
- Amino Acid (Russy White)
- Bread (unidentified, but briefly assumed by Hobbes in order to help Calvin rehearse)
Bread: "Glucose is the body's main energy source!"
Onion: "In addition to supplying vital nutrients, many vegetables are a source of dietary fiber."
The children probably stepped forward in turn, and recited what their character did in terms of nutrition. The play was cut short because Calvin went missing in the boys' bathroom, stuck in his costume.
One of the janitors had to find Calvin, later at home Calvin told his mom that the play was ruined, but he remembered his line.
This is the one and only scene when Calvin mentions a Star Wars character, "Jabba the Hutt."