The only thing scarier than being a monster is babysitting one.
Everything seems to be changing for the better at Hotel Transylvania. Dracula’s rigid monster-only policy has finally relaxed, and the hotel is opening up its doors to human guests. But, behind closed coffins, Drac is worried that his adorable half-human, half-vampire grandson, Dennis, isn’t showing signs of being a vampire. So, while Mavis is busy visiting her human in-laws with Johnny—and in for a major cultural shock of her own—“Vampa” Drac enlists his friends Frank, Murray, Wayne and Griffin to put Dennis through a “monster-in-training” bootcamp. Little do they know that Drac’s grumpy and very old, old, old-school dad, Vlad, is about to pay a family visit to the hotel. When Vlad finds out that his great-grandson is not a pureblood, and that humans are now welcome at Hotel Transylvania, things are going to get batty!