Director Guillermo del Toro’s name has become synonymous with his trademark monsters, from the wild but lovable comic book creature Hellboy to the terrifying, eyeball-palmed pale faces of the dark fantasy Pan’s Labyrinth. Del Toro has even published a book celebrating this work, aptly titled Guillermo del Toro: At Home with Monsters, and there’s an exhibit of the same name at the Minneapolis Institute of Art through the end of May.

What is del Toro’s philosophy of monster creation? How has he brought such memorable creatures to life on screen? The director admits that “monster creation, to me, is one of the hardest forms of creation,” but he recently took to Twitter to try to share his process.

In fact, it looks like del Toro is running something of a de facto film school on Twitter; last month, he tweeted a breakdown of David Fincher’s 2007 film Zodiac. In language far more poetic than your average Twitter feed, del Toro’s analysis begins, “Every great movie works at many levels. Some are evident: the dramaturgy, image crafting and sound as storytelling tools, staging, editing and acting, but then the truly great movies have deeper roots. In the case of Zodiac, all the formal elements become a quasi-hypnotic all—It lulls you into a different world and takes what was real and makes it symbolic.” Today, del Toro used Twitter to opine on “desirable imperfection,” which is certainly at the heart of any good monster. 

Evidenced in del Toro's monster class, the amount of expertise packed into a mere 13 tweets is almost as astonishing as one his creations from Crimson Peak. Here’s his wise advice on designing creatures.

1. Inspiration comes from powerful sources

The artisanal monster-maker admits that he looks inwards to reconcile the “imbalance between beauty and tragedy and rage” that many artists face. However, for monsters to be most effective, del Toro insists that “they need to draw from a multitude of sources: myth, literature, nature, and our own spirit.”

This philosophy is especially evident in his faun from Pan’s Labyrinth, which originate from Roman mythology and combine all of these elements.

2. Tone and environment are as important as creature design

Del Toro marks tone as a distinguishing factor in the process, noting that “the monster design must be of a piece with all other elements of the picture, both visual and aural.”

"Imagine designing a fish and not providing it with a proper aquarium," he continues. "Such is the delicate task of designing a monster and its environment. It is a multi-layered task and one that uses image as a storytelling device."

3. Think about all the angles

"Like a piece of art," del Toro points out, "a glance at the monster tells you its story and purpose and what it represents." Therefore, every design decision must be made conscientiously.

"First, shape and outline," says del Toro. "Then, it must be entirely expressive sculpturally. Painting comes next, and it must be counterintuitive to sculpture. Remember: painting is 80% underpainting and layering. All painting and sculpting must be 'proofed' from all angles by using a movable work light."

Del Toro also urges you to remember that every angle that an audience might see your creature from should be interesting on its own, and that “full body and bust composition must reveal new values.”

4. Direct your actors to convey the full character

We’ve got the creature’s backstory, environment, and appearance, but now it needs to come to life. Much of this happens through movement.

Del Toro advises you to "direct the actor like a performer and not an impersonator [by giving] emotional, concrete cues like arrogance, innocence, or majesty" in order to convey character. Perhaps the filmmaker’s most profound advice comes next: "A monster should change and reveal as you watch it. And at its core the vital spark: mystery."