Billy Frankenstein tells the story of a kid named Billy Frank (Jordan Lamoureux), who is related to the distant Victor Frankenstein, along with his artistic mother, Sandy (Melissa Williamson) and workaholic father George (Daran Norris).

He invites the Franks to move into the castle in the hopes of using Billy (who is the latest relative to Frankenstein) to bring the monster to life.

Frogg is hired by a man named Otto von Sloane (Vernon Wells), and his lady Fraulein (Griffin Drew), to scare the Franks into selling him the castle and make way for a mall.

Soon though, the monster begins to run out of power and so Billy and Bloodstone take him back to the lab basement to recharge him.

George announces that he got fired from his job, but is not worried because of his family importance and inheritance to the castle, but Billy and Sandy tell him that the lawyer had told them earlier in the film that they need to raise $25,000 to buy the castle, so George comes up with the idea of inviting Sloane to dinner to discuss the payment.