It's no secret that Nightmare Before Christmas writer and producer Tim Burton is a huge fan of classic monster films and various other oddities of old cinema. In 1982, he directed the animated short Vincent, in which a young boy dreams of becoming like his idol, the beloved classic horror master Vincent Price (who narrates the film). Shortly after, Burton directed the live-action stop-motion short Frankenweenie, which would be expanded as a full-length animated feature in 2012. In both versions, a boy named Victor Frankenstein (his name taken directly from Mary Shelley's original Frankenstein novel) resurrects his beloved pet dog. This love of monsters of movies past comes through loud and clear in the Halloweentown setting of The Nightmare Before Christmas, where the entire populace is monstrous in appearance and fun-loving by nature.
Very young audiences might understand through cultural osmosis that the characters they're seeing are well-known monsters, but it's far more likely that adults will notice that they're frequently references to specific literary and film monsters. Dr. Finkelstein (William Hickey), the mad scientist who created Sally and helps Jack conjure up a skeleton sled team, continues to draw on Burton's penchant for Frankenstein, for example. Other recognizable monster references include Igor, Mr. Hyde (who has multiple versions of himself hiding under his hat), the Wolfman, and the Undersea Gal, who strongly resembles the Creature from the Black Lagoon.