Hey, parents! Have your kids been asking one too many questions about the Necronomicon? Are you worried that your child might be making her way down to the seas each night to commune with the Great Old Ones?

If you’re a fan of H.P. Lovecraft, the 20th-century horror writer whose legacy looms large over us all, and you’re afraid the Elder Gods might be calling to your offspring, you’re in luck. You can now teach them how to avoid the terrors of the deep with a beautifully illustrated, tongue-in-cheek Lovecraftian alphabet book that’s newly available as a free, downloadable PDF. It’s a must-read for anyone who’s looking to learn the basics of the author’s signature brand of weird fiction ... or who just wants to terrorize their family.

Mythos ABC offers a simple primer to many recurring elements of Lovecraft’s work

In the early through the mid-20th century, Lovecraft popularized a horror subgenre known as weird fiction, characterized by an emphasis on cosmic horror and the unknowable horrors of the universe. In practical terms (at least for Lovecraft), this usually equated to the existence of many terrifying races of sea creatures and giant, tentacled sea monsters — like his most famous creation, Cthulhu — lurking just off the New England coastline.

These pesky creatures go by many indecipherable names — like the Elder Gods or the Great Old Ones — and tend to loom in the distance as an unspeakable horror that threatens to spawn and infiltrate human societies.

Unfortunately, Lovecraft was also an extreme racist who was deeply committed to eugenics. His fear of racial miscegenation translated to a recurring theme in his work, which usually depicted humans as members of cults who worship the creatures — and who eagerly breed with them as a result. This nearly always led their descendants into a dark spiral of madness.

This world and its inhabitants are the primary subjects of Mythos ABC, a collaboration between Danish writer Mads Brynnum and a host of talented artists. The book was crowdfunded on Indiegogo last year, and after publishing the book in Danish, Brynnum made the English version available to backers. Now he’s posted it online for all to enjoy — or cower in terror at.

Here’s how Brynnum describes the Lovecraftian universe:

In Lovecraft’s world evil isn’t out to get man – it just doesn’t care about us. And almost all of his stories deal with meeting the unknown and what it does to our fragile mind. Or as he himself puts it: "The oldest and strongest emotion of mankind is fear, and the oldest and strongest kind of fear is fear of the unknown."

It’s perfect fodder for a bedtime story, right?

Mythos ABC runs through a litany of Lovecraftian creatures — but it also references the wider mythos of weird fiction that both predated and followed Lovecraft. Writers like Ambrose Bierce and Robert W. Chambers all used and borrowed allusions from one another’s works of cosmic horror, which in turn made their way into Lovecraft’s own fiction and were subsequently sampled by those who came after him.

This page for H, for example, references Hastur, a figure from the annals of weird fiction that had previously appeared in The King in Yellow, a classic Chambers story from 1895. The rhyme on the page alludes to the Yellow King as well:

The book also references specific Lovecraft short stories, like his famous "The Cats of Ulthar":

Brynnum told Vox that the basic idea behind the alphabet book concept is that "each letter is about some creature or thing from Lovecraft's works, and that the rhyme ideally highlights the letter in question." Many key players from Lovecraft’s monster menagerie are on display, from Cthulhu and R’lyeh to Shoggoths and Yog-Sothoth. So, too, are the unknown, far-off places and mysterious cosmic corners of the universe that recur in Lovecraft’s writing:

Most of the artists featured in the book are Danish illustrators, but Brynnum also discovered additional contributors online, through their Lovecraftian fan art.

Brynnum said he decided to share the full book for free "just to get it out there." He’s also recently released a Cthulhu Mythos board game, Madness at Midnight, which lets you "control a gang of deranged cultists trying to summon their Lovecraftian god of choice."

Clearly, the world of Lovecraft is alive and still terrifying — which is exactly why we need a children’s guide to it.

"Basically it's just a way of teaching kids about the Great Old Ones," Brynnum said. "Because if you don't do it, someone else will."