Easter egg: Go to the page for scenes 13-16. After you wait for a while,(Note: a lot of patience is required to find this) a 17th scene will appear. Click on it and it will take you to a page with secret military files. Unfortunately, only three of them actually work. Only time will tell how to access the other ones.
Easter egg: On Disc 2 of the Special Edition, select Special Features and then select Alternate Endings. Highlight Alternate Ending 1 and press left. The Statue of Liberty's eyes will turn red. Press Enter to view how the bridge scene was originally going to look but animated and with a voiceover.
Easter egg: On Disc 2 of the Special Edition, select Special Features. Document 01.18.08: The Making of Cloverfield should then be highlighted. Press left and a red box with a cross in it will appear. Select this to view Attack of the Green Xs. To view this on the 1-disc Standard Edition, go to Scene Selection, highlight Chapter 10 and then press up.
Easter egg: On Cloverfield [Limited Edition] Disc 2, in the Deleted Scenes menu, highlight 'Congrats Rob', press the right direction key to highlight the horse's collar and press Enter. Also, highlight 'I call that a date', press left directional key to highlight the saddle on the horse and press Enter to see a humorous "deleted" scene.
Easter egg: On the Set Up menu, highlight Espanol subtitles and hit right. A helicopter should appear. Hit enter to see a montage of the cast and crew quoting some sort of catchphrase. To view this on the 2-disc Special Edition, highlight Svenska subtitles and then press right.
Chosen answer: The actors and crew were kept in the dark as much as possible, unless the information was needed for their performance. They didn't know what the parasites looked like until they began filming the subway scene. Actual-size, realistic puppets had been made for filming but were decided to look too artificial and slow on camera, but it gave the actors a chance to see what they would be running from, how their jaws and legs worked, etc. As for the main monster ("Clover"), actors would only know what was in the script and what the director told them.