There was only one reason to make “Hotel Transylvania 2” — $358 million.

The computer-animated “Hotel Transylvania,” released in 2012, earned $148 million domestically and $210 million internationally. Aimed at young children, the original film brewed a concoction of sanitized monsters, including Dracula, a mummy, a werewolf and the Frankenstein monster, into a slightly entertaining story. Slight as it is, “Hotel Transylvania” was too profitable to not resurrect in a sequel.

The Drac pack returns in “Hotel Transylvania 2.” Adam Sandler’s family friendly, hotel-operating vampire again leads the cast.

The most notable thing about this sequel is its lack of ambition. Next to the animated features from Pixar, Disney and Universal, “Hotel Transylvania 2” barely tries to be anything except ordinary. The jokes fall flatter than a wingless rodent. The animation is mediocre. But even if “Hotel Transylvania 2” deserves, on balance, a stake through the heart, it has heart.

Dracula’s daughter, Mavis, and her human boyfriend, Johnny, get married in the sequel. Later, during some high-adventure dad-and-daughter flying in their cute bat forms, Mavis tells her dad that she’s pregnant. Even though Dracula knows that the child is, unavoidably, half human, he longs for the sound of flapping little vampire wings in his castle.

After Mavis gives birth to a boy named Dennis, Dracula becomes the most possessive, obsessive of grandparents. He can’t wait for his grandson’s fangs to grow in. Mavis, on the other hand, is OK with the possibility that her son may not have inherited his mom’s vampirism.

“Hotel Transylvania 2” is largely about the tension between what Dracula wants and what Mavis thinks is best for little Dennis. That’s where the movie’s heart comes in. Dracula is horrified at the thought that Mavis, Johnny and Dennis may move out of the castle. How could she do that to him?

Mavis wonders if her daddy’s world, including its many monsters and a litter of werewolf pups that play rough with Dennis, are a dangerous environment for her son. During a trip to California to see her husband Johnny’s parents, she thinks Johnny’s homeland would be a safer place to raise Dennis.

Sandler’s Vampa Drac plots behind his daughter’s back, hoping to prevent the looming tragedy.

Sandler is the movie’s most amusing character. That’s a low threshold to begin with, and it’s downhill from there. Andy Samberg’s Johnny is goofy. Selena Gomez’s Mavis is stuck with bad lines and dumb situations. And none of Dracula’s monster friends — Kevin James’ Frankenstein’s monster, David Spade’s invisible man, Keegan-Michael Key’s Murray the mummy, Steve Buscemi’s Wayne the werewolf — say or do anything interesting.

At least it’s a nice surprise that show business veteran Mel Brooks is the voice for Dracula’s father, Vlad. Turns out this allegedly fundamentalist vampire is just a Jewish pussycat, an ancient sweetheart.

Much of “Hotel Transylvania 2” feels like an excuse for the big battle scene that comes near the end. The movie finally rises from its dullsville crypt — and then it’s over, ending with no good reason to make another sequel, other than another big international box office haul.