- Jerkass Woobie: Roscuro qualifies, although his HeelFace Turn drops the Jerkass part.
- Tear Jerker: You will cry. You will cry a lot.
- Ugly Cute: Miggery is intended to be pig-like, but when you realize what a sweet person she is, and that she does all of her bad deeds because she's so lonely, you can't help but find her adorable.
- The Woobie: Despereaux and Mig both qualify.
- Big-Lipped Alligator Moment: Boldo the Magical Soup Genie, a man made out of fruit who suddenly appears out of nowhere once the chef starts making soup again. You'd assume he's imaginary, but nope - he's an actual, physical being who directly interacts with other characters, dies, and is never mentioned again. His entire existence fits the points perfectly: a character who is weird by the film's standards, who comes out of nowhere, and dies shortly after, never being mentioned again.
- Complete Monster: Boticelli Remorso is the cruel leader of the lower rat world. Believing the only true meaning of life is other people's suffering, he forces innocent mice, such as the protagonist, Despereaux, into incredibly one-sided gladiator-like games in a Colosseum, pitting them against a gigantic cat where the only outcome is being eaten and dying in front of a crowd of bloodthirsty rats. He despises Princess Pea for no apparent reason, and as such orders his hundreds of rats to eat her, trample her and cause her great pain. Boticelli's evil is further cemented by the skulls and bones littered throughout Ratworld.
- Magnificent Bastard: Roscuro used to be a rat living in a ship, accidentally causing the death of the Queen of Dor due to his imprudence and causing Dor to become a gloomy place. Taken by the tyrannical Boticelli Remorso, Roscuro becomes his servant, helping him in the oppression of the other rats of the rat world with guilt, even helping Despereaux due to their mutual curiosity for the outside world. Intending to atone for his actions, Roscuro tries to apologize to Princess Pea but is harshly rejected. Resenting that, Roscuro manipulates the naive Miggery "Mig" Sow to kidnap the Princess by faking kindness before locking her in a room. Realizing his own awfulness after seeing Pea's despair, Roscuro betrays Boticelli and dooms him to his death, apologizing for his actions and returning to his life at sea after Dor returns to its former radiance.
- Uncanny Valley: Princess Pea. Her body is the same proportion as the other humans, yet her head is about twice as large with a forehead that could hold a heliport.