NOTE: This spoiler was submitted by Jeremy

The film opens with a montage of Dracula (Brian Hull) and Mavis (Selena Gomez) from over a century earlier when the count had just begun to build and open Hotel Transylvania. In the present day, Johnny (Andy Samberg) throws together a celebration for the hotel’s 125th anniversary. However, Drac finds the displays to be too much for him, and things start to get chaotic when the other monsters join in for a show. Drac uses his powers to freeze everyone and fix things up to his liking. Mavis says that Johnny did his best to impress Drac, but Drac asks her if there is nothing that she could change about Johnny, and Mavis says no because she thinks he’s perfect the way he is.

Drac takes a breather outside and is joined by Ericka (Kathryn Hahn). She brings up Drac’s impending retirement, which Mavis overhears since she has supersonic hearing. Drac is indeed planning to pass down the hotel to Mavis and Johnny, but he is in doubt over Johnny’s capabilities of handling the hotel. Mavis gets excited and spills the beans to Johnny, who becomes twice as excited.

Johnny finds Drac backstage as he is planning to get ready to announce his retirement and passing down the hotel to Mavis and Johnny, but when Johnny comes in and starts spouting off his ideas, Drac panics and lies to him, saying that due to a “monster real estate law”, a human cannot inherit the property. Johnny is disappointed, but when Drac realizes he still has to give an announcement, he makes up something lame, and Johnny blames himself for not being a monster. Van Helsing (Jim Gaffigan) overhears his predicament and offers him a solution.

Van Helsing brings Johnny to the basement where he lives and shows him his Monsterfication Ray, containing a special crystal that can turn humans into monsters and vice versa. He demonstrates on his pet guinea pig Gigi, turning her into a large purple monstrosity with huge teeth. Johnny zaps himself with the ray and turns into a huge lizard monster. Drac overhears the commotion and finds Johnny as a monster. He is excited to show Mavis his new form so that they can have the hotel, but Drac knows Mavis will freak out, so he grabs the ray and attempts to zap Johnny back to humanity. During the chase, Drac has to hypnotize Dennis (Asher Blinkoff) and Winnie (Zoe Berri) into not saying anything to anybody. Just when Drac thinks he has a clean shot, he gets hit with the ray and begins to turn human, falling down into the pool below. A stray shot also hits the ice sculpture in the lobby and affects the punch in the fountain.

Johnny goes to find Drac, and is joined by the other monster friends – Frank (Brad Abrell), Murray (Keegan-Michael Key), Wayne (Steve Buscemi), and Griffin (David Spade). They are surprised to see Drac as a human, and he is horrified to see himself. To make matters worse, the crystal is broken, so the ray no longer works. Drac and Johnny go to Van Helsing and learn that the only place to find a new crystal is in a cave in the jungles of South America. Drac and Johnny head out to make the trip, but he asks the other monsters to cover for him and not tell Mavis what happened. The gang is annoyed at always having to cover for Drac, so they decide to mind their business. They are joined by Blobby (Genndy Tartakovsky) and drink from the fountain, and they start to turn human. Murray becomes an old pharaoh again, Wayne loses all his fur and just becomes a guy with a beard, Griffin is revealed to be naked, and Frank becomes a hunk, to the disgust of the others (but he’s happy about it). Blobby just turns into a jello mold on a plate.

Drac and Johnny take a plane to South America. When they arrive, Drac thinks the sunlight will still hurt him, but Johnny reminds him he can stand in it now. Drac takes a moment to appreciate the sun until he stares too long and it begins to scorch his eyes. He starts blindly wandering into traffic until Johnny goes in and rescues him. When trying to call for a cab, Johnny accidentally breathes fire, causing a pile-up in the road of startled drivers. Meanwhile, Van Helsing notices that Gigi is growing bigger and more monstrous.

Back in the hotel, the four monsters-turned-human try to sneak past Mavis and Ericka, plus Wanda (Molly Shannon) and Eunice (Fran Drescher). Unfortunately, they are found anyway and have to explain themselves. Eunice is disturbed by pretty boy Frank while Wanda is not happy that Wayne doesn’t have to deal with the pups now that he’s not a wolf. Everyone then sees a news report on Drac and Johnny being spotted, forcing the others to come clean about what happened. Mavis and Ericka go to find Van Helsing, who is still struggling to keep Gigi under control. He tells them that the effects of the Monsterfication Ray on humans will be irreversible if not fixed in time, meaning Johnny will lose all semblance of humanity and remain a mindless beast. Mavis and Ericka then plot to take a trip to South America to save them.

Drac and Johnny trek through the jungle on foot, with Drac suffering human effects like mosquito bites, body odor, and everything in nature that can kill you. When they stop at a beautiful waterfall, Drac jumps in the water and is bitten by piranhas. Drac gets stressed when he sees that the path to the crystal is incredibly far away. Johnny also ends up taking them on a wrong turn up a large mountain, which they then fall off of. Drac then sees that Johnny has grown wings and tells him to fly, which he manages to do and saves himself and Drac from falling. Johnny then gives his wings a test fly.

Mavis and Ericka bring the monster gang (plus Wanda, Eunice, and the pups) along for the ride in a blimp. When they get close enough, they drop out of the blimp and ride a jeep through the jungle. Mavis uses her hearing to try and pick up any noise to track Drac and Johnny, and she hears Johnny singing.

Drac and Johnny sit by a campfire where Johnny shows Drac how to roast a marshmallow. He explains that although it looks black and burnt on the outside, inside is the soft and sweet gooey center that one has to look for, which he applies to other things in life. Drac suddenly feels upset about lying to Johnny, but just as he is about to come clean, Mavis, Ericka, and everyone else ride in. After the two of them press Drac for an explanation, he reveals to Johnny that he lied about the monster real estate law because he was worried about Johnny changing too much of the hotel to his image. Johnny feels betrayed, and the anger builds up inside of him to the point that he becomes even more monstrous. He stomps out of the jungle, and Mavis goes to find him while asking Ericka to let her know when they have found the crystal.

Drac and the gang ride the jeep into the caves where they eventually find the crystal’s location. Once inside, they get lost in a hall-of-mirrors type of cave with all the crystals confusing everyone. Ericka informs Mavis, who has found Johnny now as tall as a skyscraper. She briefly gets through to him, but his anger at Drac not accepting him as part of the family keeps him enraged and beastly. Ericka sends Mavis the location to the cave, and she flies in her bat form over there with Johnny chasing after her.

Mavis makes it to the cave just as the sun starts rising. She finds Drac and the others, but Johnny begins pounding on the walls outside the cave, causing the crystals inside to crumble and come down. The gang finds the main crystal they need, and Mavis goes to try and use it on Johnny, but he keeps breaking through the walls and causing the sunlight to come through. The other monsters and Ericka use their bodies to shield Mavis from the sun and get her high enough so that she can hit Johnny with the human setting on the ray. It doesn’t seem to work, as Johnny is still an angry monster. He grabs Drac, who then tries talking to Johnny. He admits that while he was originally not accepting of how Johnny is, he still views him as part of the family and says that he has helped Drac see the “marshmallow” part of things in life. This brings out Johnny’s humanity, and Mavis is able to transform him back into a human. She joins her husband and dad as they all share a group hug.

The gang flies back to the hotel after everyone is returned to their monster forms. Just as Drac is set to pass on the hotel to Mavis and Johnny, they are all horrified to see that the hotel has been destroyed by Gigi, but Van Helsing, Dennis, Winnie, and other monsters are okay. Drac turns Gigi back to normal but is heartbroken at the destruction of the hotel. Mavis and Johnny try to comfort him and say they will rebuild it the way it was, but Drac tells them that since it is theirs now, they can rebuild it however they see fit.

One year later, the hotel celebrates its grand re-opening. Drac is stunned to see that Mavis and Johnny rebuilt it exactly the way it looks on the outside, but they show him that they added new workout facilities, pools, and tanning beds to benefit the other monsters. Drac is surprised but happy and proud.

Brought to you by

While celebrating Hotel Transylvania's 125th anniversary, Mavis overhears that Dracula wants to retire and pass down the hotel to her and Johnny. However, Drac fears that Johnny will change things in the hotel to his liking and make it more modern than he would like, so he lies to Johnny and says only a monster can inherit the hotel. Johnny goes to Van Helsing, who has created a Monsterfication Ray to turn humans into monsters and vice versa. Johnny transforms into a dragon-like creature, but when Drac tries to change him back, he gets himself turned into a human, and his friends - Frank, Wayne, Murray, Griffin, and Blobby - also end up as humans.

The crystal in the ray is broken, so Van Helsing tells Drac and Johnny that they need to travel to South America to find a new crystal to change them back to normal. Soon, Van Helsing learns that the monster effects from the ray can cause irreversible changes, making the subject into a mindless monster, which Johnny will be stuck as if they don't make it on time. Mavis joins Ericka and the other monsters in going to help them.

Drac and Johnny bond through their adventure, but when the rest of the gang arrives, Drac admits that he lied to Johnny so he wouldn't pass the hotel down to him. Johnny feels betrayed, and his anger causes him to become even more monstrous. Mavis goes after him while the others find the cave with the crystal. She gets Johnny to follow her and grabs the crystal to turn him back. It doesn't work until Drac apologizes to Johnny and accepts how he has changed his life, bringing Johnny's inner humanity out so that Mavis can change him back for good.

While the monsters return to their normal forms, they return to find that the hotel was destroyed by Van Helsing's guinea pig Gigi that got turned into a monster. Drac still passes down the hotel to Mavis and Johnny, and one year later, the hotel is back in business with some slight alterations.