Curious 'Creatures'

Dragons, mermaids, and one-eyed monsters scare - and inspire - in an exhibition that reminds us why there's comfort in the creepy

You can explain to a little boy why you are moving to the other side of the world. But if you haven’t yet introduced him to a world map, or indeed to the concept of ‘‘the world,’’ you might as well point and say, ‘‘There be dragons.’’ In the weeks and months after my family and I moved from Sydney to Boston this year, we were, I’m convinced, in shock. What had we done? We had a 1-year-old girl and a 3 1/2-year-old boy. Their world in Sydney had been thick with family and friends. In Boston, my wife and I lay awake in bed at night, marveling at what we had just done as a sea monster might marvel over a ship it had wantonly wrecked. Our little boy’s responses were more human. We watched him be-come surly and sullen as he tried, and failed, to make sense of it all. None of our explanations really registered. He was angry. His favorite toy was, and still is, a hard plastic dragon with yellow eyes and powerfully extended wings. A scary-looking thing. But Tom assimilated it to his own purposes by calling it ‘‘Hero Dragon.’’ He gave it a status one rung above all the other animals in his menagerie: the platypus, the elephant, the penguin.

"Daddy, will you come and play with me?" was his plaintive refrain, and it had only one possible interpretation. It meant: "Hurry up and tell me a story about these animals, and make damn sure that the story involves some of the animals finding themselves in great danger, and being rescued by Hero Dragon."

When an invitation arrived to the Museum of Science's new exhibit, "Mythic Creatures: Dragons, Unicorns & Mermaids," I asked my wife to stay at home. Tom and I and Tom's little sister, Leila, were going to go see it, and if things went to plan, we would also cruise through the museum's other new show, "Goose Bumps! The Science of Fear."

Things, needless to say, did not quite go to plan. Tom spent most of the day clinging like a limpet to my thigh, while Leila, now 18 months, tore around the two exhibits like a cheetah cub in a field of fawns.

Never mind. "Mythic Creatures" was a revelation, an unabashed crowd-pleaser which also had fascinating things to say. The multimedia extravaganza is divided up neatly according to the elements, so we have "Creatures of Water" (sea monsters and mermaids), "Creatures of Land" (griffins, unicorns, and super-sized apes), "Creatures of Air" (phoenixes, sphinxes, and garudas) and, finally, "Dragons" (presumably to be read as "Creatures of Fire").

The first thing you encounter is a model of a 17-foot-long dragon with fairly conventional attributes: wings, scales, a long tail with an arrow tip. By the time you get to the end of the show, you've been exposed to dragons and other mythical creatures from cultures all over the world. They appear on textiles, coins, Japanese suits of armor, and maps, and they come in the guise of Aztec gods, Aboriginal yawk-yawk spirits, Asian garudas, and Greek sphinxes.

No question, we three emerged with a vastly improved repertoire of fantasy creatures to draw on whenever our imaginations require it.

And that's the point, isn't it? Our imaginations do require dragons, monsters, and mermaids. When we know something is out there but we don't yet know what it is, these creatures are what we invent to fill the void. We construct them out of what we know and what we don't know: The two are related in the most intricate and fascinating way, which is what the show demonstrates.

Was, for instance, the Cyclops - the one-eyed monster referred to in ancient Greek literature and myth - just invented out of thin air, so that Homer could flesh out his yarn with a bit of local color? Maybe. But according to paleontologists, as we learn in the show, a likelier explanation is the discovery by the ancient Greeks of prehistoric dwarf elephant skulls in Greece and Sicily. These skulls, about twice the size of a human skull, have a huge cavity in the middle (for the trunk) which could easily have been mistaken for a single eye socket belonging to a giant.

Similarly, carcasses believed to be evidence of sea monsters were often the dead bodies of real creatures such as basking sharks or giant squids. And a bird described by Arab traders as big enough to lift an elephant may have been a response to the now-extinct aepyomis, which was more than 10 feet tall, laid 2-gallon eggs, and lived on the island of Madagascar.

Of course, it's a delicate business, this relationship between reality and invention. It can easily get out of control. For very small children, in particular, the point of imaginary things is very often that they should stay in the imagination. When a 3-year-old who loves his toy dragon walks into a show and the first thing he sees is a huge dragon with a 19-foot wingspan, it's perhaps no surprise that his imagination feels violated and wants to batten down the hatches.

But this show cleverly balances spectacular re-creations of mythical creatures with smaller items that fire the imagination, demonstrating along the way that many of the most fanciful creatures have sources in reality.

One of the loveliest items (it actually induced Tom to let go of my thigh) is a simple model of waves in the sea. You turn a wheel, and with each rotation, dolphins arc out of the waves before slipping back out of sight.

What must it have been like, this simple conceit made me wonder, to spend weeks and months at sea, floating on the cusp of something so vast, unknown and invisible, long before science had provided a credible picture of what lay beneath?

No wonder sailors became such good storytellers. And no wonder they invented creatures like the mermaid, which so perfectly embodied their complicated feelings about the sea, as beautiful, seductive, and dangerous.

Pairing this show with "Goose Bumps! The Science of Fear" - billed as the "the word's first exhibit on fear" - makes a lot of sense. If your kids are just a year or two older than ours, you'll probably love it. For me, with Tom and Leila in tow, going from one to the other was like expecting to be saved from a shipwreck by a shark.

Tom managed to put his terror on hold just long enough to reveal a sadistic streak, as we watched viewers putting their fingers into dark enclosures that might or might not contain spiders or snakes, anticipate electric shocks and fall backward, all in the name of science.

But frankly, the exhibit's affected atmosphere of detached inquiry was almost spookier than the music. We returned briefly to the cresting dolphins in "Mythic Creatures," and then it was time to hurry home - to Hero Dragon, and Mom.

Sebastian Smee can be reached at ssmee@globe.com.