This movie is set in an alternate universe from the original series and features many changes to the original Monster High characters. In the original series, Deuce was dating Cleo instead of Clawdeen (although this film states several times that he broke up with Cleo), Lagoona was Australian with blue skin instead of Latina with pink skin, Ghoulia spoke in moans instead of speaking normally, and some of the characters had distinctive accents (like Draculaura's Romanian accent, Clawdeen's New York accent, and Abbey's Russian accent) which were changed to normal American accents for the reboot.
Frankie states that they were built from the parts of multiple dead geniuses including parts of the brains of Albert Einstein, Marie Curie, and Plato, "some lady named Liz who apparently invented the internet but didn't get any credit" (presumably referring to Elizabeth Jocelyn "Jake" Feinler ), the cortex of Alan Turing, the heart of William Shakespeare, and the right hand of Frida Kahlo.