"Frankenstein: A Monstrous Parody," by Rick Walton and illustrated by Nathan Hale (Feiwel & Friends, $14.99) (Feiwel & Friends)

Blame the ghoulish humor of Rick Walton, the author of more than 60 books for children. He and illustrator Nathan Hale have published “Frankenstein: A Monstrous Parody.” Anyone who loves Ludwig Bemelman’s classic, will be howling at the moon over this witty mash-up. It’s the latest in a growing crypt of hilariously wicked kids books that includes Michael Rex’s “Goodnight Goon” and Judy Sierra’s “The House That Drac Built.”

Published by Feiwel & Friends — or, in this case, Feiwel & Fiends — “Frankenstein” opens with a ghoulish echo of Miss Clavel’s Catholic boarding school:

In a creepy old castle all covered with spines,

lived twelve ugly monsters in two crooked lines.

In two crooked lines, they bonked their heads,

pulled out their teeth, and wet their beds.

Two years ago, Walton and Hale posted their story of Frankenstein and Miss Devel on Hale’s webcomic blog, but the electrifying response from readers has zapped it ALIVE in print. Stepping carefully around the legal terrors of parody, they offered a copy of “Frankenstein” to the publisher of the original Madeline books and received no objections.

Walton told me via e-mail from his home in Provo, Utah, that he was a big fan of MAD magazine as a kid. “I grew up listening to Spike Jones, Allen Sherman, PDQ Bach.” Take-offs like this, he says, let “me be the goofy me, the horror me, as well as the authors of the originals. I get to be several people at once. Kind of like Frankenstein.”

Striking that devilish balance between the original and the transformed version is what makes this book — and all good parodies — so enchanting. “The story needs to stand on its own, able to be enjoyed by people who are not familiar with the original, otherwise it’s just an inside joke,” Walton says. “But it has to echo enough of the original to delight those who do know the original.”

Madeline may have lost her appendix, but as this story develops, young Frankenstein loses his head. And things go downhill fast when he gets it back: “He chomped the ceiling out of habit./ Yum! he thought. It tastes like rabbit!

Parents needn’t worry about frightening their little ones. “Humor chases away threat,” Walton says. “Besides, picture books are designed to be read to kids by the adults in their lives, who can quickly decide if this book is appropriate.”

Hale, the father of a 7-year-old Madeline fan, agrees. In an e-mail message from his house near Walton’s, the illustrator says that children hearing this book “associate themselves with the little monsters. They are the monsters, the ones doing the scaring. If anything, we are making these old classic monsters less scary: the sweet chocolate of Madeline mixed with the salty crunch of Frankenstein.”

Hale says this is just the first of several planned collaborations with Walton. Who knows what the undead pair will dig up next.

Coincidentally — or not! — Mary Shelley’s “Frankenstein” begins with a letter from the narrator signed “R. Walton.”

And that’s all there is; there isn’t any more.

Ron Charles is The Post’s fiction editor. You can follow him on Twitter @RonCharles.