Hotel Transylvania: Transformania

During Hotel Transylvania's 125th anniversary celebration, Dracula is planning to retire and leave the hotel to Mavis and Johnny. Mavis overhears this and tells Johnny who excitedly tells Dracula his plans to renovate the hotel. Worried about Johnny ruining the hotel, Dracula lies that there is a "monster real-estate law" which only lets monsters own the hotel, leaving him disappointed. Professor Abraham Van Helsing decides to help Johnny by using a ray powered by a crystal that turns humans into monsters and vice versa. After testing it on his guinea pig Gigi, he uses it on Johnny who turns into a dragon. Learning about Johnny's monster form, Dracula tries to turn him back to normal but accidentally turns himself into a human, breaking the ray's crystal in the process. Van Helsing tells Dracula and Johnny that they can turn themselves back to normal by getting another crystal in the Cave of the Reflexión in South America, so Dracula and Johnny set off to do so. Dracula's friends Frank, Wayne, Griffin and Murray end up becoming humans as well, as a result of drinking from a fountain that was contaminated by the ray. After learning about Dracula and Johnny's whereabouts on the news, Mavis and Ericka confront Van Helsing, but they are attacked by Gigi. Van Helsing discovers that the effects of the ray are unstable, as the monster transformation will keep mutating until the subject becomes a mindless beast. The rest of the gang head to South America to find Dracula and Johnny. While traveling through South America, Dracula and Johnny begin to bond. During a camp-out, Johnny teaches Dracula about how if he only sees the worst in things, he will miss out on the best parts. Dracula begins to confess that he lied about the monster real-estate law, but the rest of the group finds them, interrupting him. Things turn sour when Dracula admits his deception regarding passing over the hotel to Mavis and Johnny. This prompts an upset Johnny to believe Dracula does not consider him family and to mutate further before running away. Mavis goes to find Johnny while Dracula and the rest of the gang go to the Cave of the Reflexión. Mavis finds Johnny, but the transformation has turned him very volatile. She leads him to the cave where they finally find the crystal. When Mavis tries to turn Johnny back to normal, the ray fails to work, as Johnny has been a monster for too long. Dracula lets himself get captured by Johnny and tells him he now sees him as family. This brings Johnny back to his senses, allowing Mavis to return him to normal. With Dracula and his friends finally back to normal, they return home, only to find that the hotel has been destroyed by Gigi. Dracula decides to let Mavis and Johnny rebuild the hotel to their liking. One year later, Mavis and Johnny have rebuilt and modernized the hotel.

Plot from Hotel Transylvania: TransformaniaCC BY-SA 4.0