Has it really been ten years since "Cloverfield" hit theaters, seemingly out of nowhere?

The monster movie, from producer J.J. Abrams and director Matt Reeves received, no pre-release hype or casting notices, just a buzz-inducing teaser trailer and a mysterious promotional campaign.

In the meantime, most of the unknowns in the cast have gone on to bigger things, Reeves is set to direct a solo Batman film, and the third "Cloververse" film is due in April. And yes, found footage is still a thing.

Here's some of the things you might not know about the creature feature:

1. J.J. Abrams got the idea for the film when he was in Tokyo for the premiere of "Mission Impossible 3." While there, he visited a toy store with his son and was impressed with all the Godzilla toys. "This is like a national monster," Abrams said, and he decided that the U.S. needed their "own national monster."

2. To prepare for a film that was supposedly all handheld amateur footage, Reeves told LAist that he watched a lot of YouTube videos. "A lot of the stuff that was in that first trailer, the teaser, was directly inspired by just looking at footage that people had of parties and events," the director said. He also watched "Children of Men" ("because of the continuous shot aspect of it") as well as classic horror films "Alien," "Jaws," and "The Shining."

3. None of the cast got a script or had any idea of what kind of film they were auditioning for. Reeves recalled to LAist, "[Felicity' together, she thought that when she first came in ... that the movie was going to be "Felicity-esque." It wasn't until she was called on to stab someone in the heart with an adrenaline hypodermic needle (no, that scene's not in the film) that she realized it was definitely not going to be anything like the WB series.

4. Since Abrams had just been announced to reboot "Star Trek," a lot of the actors thought that's what they were auditioning for. (Sorry, would-be Captain Kirks!)

5. The famously enigmatic teaser trailer (with the decapitated head of the Statue of Liberty) was modeled on classic, cryptic ads for "Close Encounters of the Third Kind." Said Reeves of the short teasers that aired before Steven Spielberg's classic UFO movie debuted, "It had this real scary music ... with this really scary voiceover... That voice said, 'Close encounters of the first kind,' and then it showed all this footage that was grainy and stills that looked like they could be flying saucers and it said, 'Sightings.'"

6. To keep the title a secret, Abrams printed call sheets in which the movie was labeled "Cheese," "Slusho," "Monkey," and "Chocolate Outrage." (Such a shame we're not talking about the "Chocolate Outrageverse" instead of the "Cloververse.")

7. The line in the trailer where someone (actually Reeves) exclaims, "It's alive, it's huge!" was misunderstood by many as "It's a lion, it's huge," prompting theories that it was a film about Voltron.

8. The severed head of the Statue of Liberty was, of course, inspired by John Carpenter's 1981 film "Escape From New York." In the film, the head is about 50 percent bigger than the real thing. This is because people complained it looked too small in the trailer.

9. The man yelling "Oh my God!" when the head of the Statue of Liberty lands in the street is producer Bryan Burk.

10. According to Reeves' DVD commentary, whenever a cameraman, crew member, or T.J. Miller (who shot a good chunk of the film as main character Hud) tripped or fell, they kept the footage to enhance the realism. The shot where a crowd of people is running from the Brooklyn Bridge and Hud falls, that was cinematographer Mike Bonvillain taking an unscripted fall.

11. The actors had to do 40-50 takes of each shot. Caplan told From the Front Row all that running wasn't fun: "Jessica [Lucas] definitely had it rougher than I did, since she was in high heels. I had these platform boots on and, the longer you run in them, the worse your feet feel and it was just rough. I haven't gone to the gym in like a year. So I don't know if I was really ready for it. I'm sure Mike Vogel had an easier time than I did. Because he's on the cover of Men's Health. And he's obviously very physically fit."

12. The actors were called on to hyperventilate so much, in fact, that they had to have oxygen tanks at a few points, Caplan revealed.

13. The Sephora store in the film was an abandoned building that (with the company's blessing) was dressed up to look like a real store. That was a big disappointment to everyone who lived in the area and thought they were getting their own Sephora store.

14. That slanted hallway? It was really built that way and not just the result of a tilted camera. Filming on it made a lot of the cast and crew nauseous, an element Reeves wished he had been able to convey to the audience, which he revealed in the commentary. (As if things weren't tense and uncomfortable enough as it was for the characters.)

15. The subway train track the production built for an underground sequence was relatively short, so the cast had to walk back and forth to give the illusion of a long tunnel. Overhead lighting was adjusted so audiences wouldn't catch on.

16. Reeves was told that the rats used in the tunnel were the "best rats in the business," and that they had also been used in "Pirates of the Caribbean."

17. A real incident on the streets of New York City involving a pipe bomb meant that the "landing zone" scene near the end of the film almost didn't happen. Most of it was shot on a soundstage in Los Angeles, but they still needed a shot at the intersection of 40th and Park. Luckily, on the last night of filming in New York, they were allowed to get their shot.

18. The viral marketing campaign included character videos posted to MySpace. (How 2008). They stayed up until 2013.

19. The film's shaky-cam style caused severe motion sickness among audience members and also triggered migraines in some. This prompted many theaters to post warnings about the potential risks.

20. While promoting "10 Cloverfield Lane" (which also debuted with no prior announcement), Abrams admitted that plans for a direct "Cloverfield" sequel were abandoned after the 2014 "Godzilla" and Guillermo Del Toro's "Pacific Rim" made kaijus popular again.

21. Abrams, Reeves, and producer Bryan Burk all met through their shared love of making 8mm movies when they were about 13 years old. The host of one public access show thought they'd hit it off and introduced them.