[3] It then made its first full appearance in the film, where it was seen to be 25 stories tall[4] and rampaging through New York City while being attacked by the United States military.

J. J. Abrams conceived of a new monster after he and his son visited a toy store in Japan while promoting Mission: Impossible III.

Blank described the intended goal of the creature, "Rather than the monster having a personality [like Godzilla or King Kong], it's more of an entity or an event.

[4] Although conceived by the film's creators as infantile,[8] the creature is 25 stories tall (corresponding to 250+ feet or 76+ meters)[4] and withstands missiles, artillery shells, and bombs with minimal injury.

The creature's design includes appendages on its underbelly, described by Neville Page as an "elongated, and articulated external esophagus with the business end terminating in teethlike fingers".

"[11] The viral marketing campaign for "Cloverfield" suggested that the creature was an ancient amphibious organism awakened by the drilling of Chuai Station, an oil platform of the Japanese company Tagruato which had the purpose of extracting a substance called Sea Bed Nectar that would become the secret ingredient of a drink called Slusho.

[13][14][15] Reviewing the film Cloverfield, the San Jose Mercury News described the creature as "a monster for the MySpace generation".

[16] Reviewer James Berardinelli noted, "The movie follows the Jaws rule that monsters are usually more intimidating when they are shown infrequently and only in brief glimpses.

"[17] Amy Biancolli of the Houston Chronicle described the creature as retaining "an air of mystery—a monstrous je ne sais quoi that makes him all the freakier".

[19] Roger Ebert of the Chicago Sun-Times expressed acceptance of the lack of explanation for the creature's origin, explaining that it "is all right with me after the tiresome opening speeches in so many of the 30 or more Godzilla films".

[20] Peter Howell of the Toronto Star thought that the "main" creature was disappointing, while he considered the "mutant spider crabs" that came from it as "way scarier".

[22] Todd McCarthy of Variety found that the creature was more reassuring as it appeared more in the film, explaining, "Its very nature as a walking, stalking being suggests it can somehow be killed by conventional means.

"[23] Chris Vognar of The Dallas Morning News applauded the creature's appearance as cinematic: The thrill here isn't in the critter but in how it's revealed.