Here comes The Calatrasaurus — the Port Authority’s “World Trade Center Transportation Hub,” a cyclopean PATH terminal onto which scary “wings” have been grafted like plastic mutant terrors of 1950s sci-fi movies.

Or do the wings, not plastic but steel, suggest teeth whittled down by a sadistic dentist? Or a giant fishbone? The Hub exhausts your capacity for cheap jokes.

With each passing week, the embarrassing ugliness of this $4 billion boondoggle designed by Santiago Calatrava — a hideous waste of public money — grows plain for all to see.

Not everyday-ugly, like a tacky brown tie or dress, but LOL-ugly. What are those spiky “ribs” and “wings” doing next door to 3 World Trade Center and the memorial pools?

What happened to the “bird in flight” we were promised?

The elephantine excess won’t be fully realized until the scheduled opening at the end of 2015.

But as the dragon slumbers to its feet, enough of it’s reared its head to give a sense of what the finished fiasco will look like: a self-indulgent monstrosity wildly out of proportion to everything around it, and 100% aloof from the World Trade Center’s commercial and commemorative purposes.

Hey, what’s wrong with a train station? Nothing — but today’s 40,000 daily PATH riders make do very well with the current temporary station.

And the Hub’s vaunted subway line connections could have been more efficiently achieved with a simple passageway than an “Oculus” longer and taller than Grand Central Terminal’s main hall.

Is it unfair to trash an unfinished project? Well, it’s going to look weirder, and worse, when it’s done. The wings will be twice as many as they are now. A planned white paint job of the now battleship-gray ribs beneath the wings will only sharpen the skeletal appearance.

And citizens of New York and New Jersey may well ask: The Port Authority, which is scrambling to come up with a mere $90 million to fix the miserable Eighth Avenue bus terminal, spent more than $4 billion on this?

The problem isn’t that the Hub looks different from its neighbors. A work of architecture need not “fit in” to be beautiful. “Contextualism” typically results in pastiche.

When Frank Gehry created the great Guggenheim Museum in Bilbao, he was not seeking to mimic its surroundings.

Yet, the wavy-surfaced facade commands its site with the inexpressible eloquence which only a great artist can muster.

But it does not follow from Gehry’s masterpiece that an architect should stick thumbs in the eyes of everything around a new project and say, “Look at me! I’m Calatrava!”

His vision, first unveiled in 2004, was universally hailed. I admit to being an accomplice in this: suckered by captivating renderings and models which suggested a “bird in flight,” I praised the Hub’s “lyrical buoyancy” and “optimistic and resilient aesthetic.”

But the “bird in flight” has bird-and-switched into a sharp-edged stegosaurus shorn of beauty by “value engineering” — the cost-saving strategy which alters or replaces just enough of an architect’s original vision to make it look cheap.

To make the Hub truly resemble the sleek and graceful 2004 images might have cost five times its original $2.2 billion estimate. And we all should have known better.

Of course, the Hub has been a flashpoint project for a decade due to its cost increases and the delays its infernally complex engineering caused to the rest of the WTC.

Although strongly backed by former New York Gov. George Pataki, it’s always been the pet project of the Port Authority’s New Jersey commissioners, who’ve called it the 16-acre site’s “centerpiece.”

How many Jersey commuters will actually use it? Will people really want to shop at expensive stores underground?

Yet, for all the controversy, and despite lethal changes to Calatrava’s original design, it remains impermissible in learned circles to ridicule the visibly awful result.

It’s still regarded by the Architecture-with-a-Capital-A crowd as special enough to justify in the end all its trouble and cost.

They say: Does anyone now care that Grand Central Terminal took 10 years to build, that Brooklyn Bridge construction cost 20 lives, or that creating Central Park required evicting thousands of squatters?

But the Hub is none of those. Come down from the ivory tower, guys, buy a MetroCard and examine the beast from any angle — from Church Street, or from the third floor of the Millenium Hotel, or from the memorial ground or from West Street.

The mighty steel ribs which support the wings — admittedly an impressive piece of engineering — may frighten small children.

From inside the Hub’s tentacular underground passageways, which I saw on a tour last summer, they evoke the monster-infested spaceship of “Alien.”

For a taste of their snaking menace, take a stroll through the Hub’s only segment open to the public so far — the west concourse, which connects the temporary PATH station on Vesey Street with Brookfield Place on the Hudson River side of West Street.

At once sterile and intimidating, the 600-foot-long corridor is framed by steel “articulated” ceiling ribs and a floor of parallelogram-shaped marble panels it will cost a fortune to maintain.

One day, stores and restaurants inside the Oculus might humanize the place. It’s even possible the entire Hub won’t seem so out of scale and out of place as it does today.

That will come only when 3 World Trade Center next door, now a seven-story stump, rises to its 80-story height and when and if 2 World Trade Center goes up on the other side.

Tucked between a pair of skyscrapers, the Hub might even look demure. Perhaps it will seem more curiosity than catastrophe. Until then, behold what $4 billion of bureaucracy-fed vainglory has bought us.