Each of the seven princes comes from different fairy tales based in different countries, with the characters' accents matching their backgrounds. Merlin and Arthur, from "The Legend of King Arthur", speak with a Britsh accent; Jack from "Jack and the Giant Beanstalk" speaks with a French accent; Hans from "Hansel and Gretel" speaks with a German accent, and Pino, Noki, and Kio from "Pinocchio" speak with an Italian accent.
More than half of Prince Average's lines were ad-libbed by voice actor Jim Rash which were then incorporated into the film.
The living space of the seven dwarfs has only one wall in front in order to give the illusion that they live in a castle, reflecting their vanity and false pretentiousness.
Merlin is designed as a wizard from an Eastern Kingdom, and as a result his design incorporates a number of Asian elements. For instance, his clothing is based on the Korean hanbok and the Korean characters for lightning are written on his spell charms.
The triplets are named Pino, Noki, and Kio, referencing the Italian fairy tale Pinocchio, and can be told apart by their hats with one, two, and three belts, respectively.