Fred Jones (Scooby-Doo) pen-pal, Alejo Otero, a man who lives in Veracruz, Vera Cruz, Mexico, invites Fred and the rest of the gang to visit him and his family there. Fred and the rest of the gang talk about it until they decide to go. However, after Alejo sent the invitation to Fred, a big long-haired monster started to terrorize the population of Veracruz. Alejo and his young son, Jorge, and their pet Chihuahua (dog), Chiquita, see the monster, and the locals start calling him "El Chupacabra".