- Everyone Is Jesus in Purgatory: The book has been subject to countless interpretations in literature classes, to this day.
- Freud Was Right
- Paranoia Fuel
- Squick: The giant cockroach-form, which leaves a slime trail behind it. Also when Gregor suddenly finds that he no longer likes his favorite human foods, and prefers old rotten garbage instead.
- The Woobie: Even as a bug, Gregor just wants to live happily with his family. They are repulsed by him and decide that everything's better if he's dead.