Taken from the wiki:
Species Unknown amphibous species
Height 350 feet
Weight 5,806.04 metric tons
Length 1,200 feet
Abilities Has extremely thick skin, which is heat-resistant and enables it to thrive in extremely high pressure environments, as well as cope under heavy fire from human weaponry, great physical strength.
Origins Undersea life form.
The monster came from the Atlantic Ocean, where it was awakened by Tagruato submarines sent down from Chuai Station to investigate. The monster rampages throughout Manhattan, destroying the city in its path.
The monster is a deep-sea creature with an unknown evolutionary history. The species apparently has a very long life-span, as the creature is still an infant during the events of the film, regardless of being alive for thousands of years. It grew to its massive size through consuming large amounts of Seabed's Nectar, a natural steroid-like substance which is very addictive and causes increased cell division and growth, and is used by Tagruato's subsidiary company, "Slusho!", for use as their secret ingredient in their frozen drink of the same name. At some point afterwords, the monster went into a sort of hibernation.
The monster was first discovered by one of Tagruato's marine biologists, Kazui Ichigawa. Tagruato later stole his laptop and files and killed him and his family while they were on vacation in Daisetsu-San National Park, covering the assassination up as the result of a gas explosion in their trailer. Later, they used this information to locate the monster and built the Chuai station over top of it, claiming (falsely) that they were drilling for oil there.
Shortly before the rig was supposed to open, Tagruato sent several submarines from the station down six miles to the ocean floor to study the monster. This action disturbed the creature from its slumber, and in a fit of rage and fear it destroyed the station, then proceeded towards Manhattan.
The creature, upon arriving to New York City, attempts to eat the Statue of Liberty's head, then throws it into the city when it realizes the head isn't edible. Though initially confused, the military's subsequent attacks frighten and later enrage the monster. For approximately five hours and fifty-seven minutes, it rampages throughout the city, destroying landmarks and battling the military. After several failed attempts to kill the monster, the government initiates the HAMMER-DOWN Protocol, in a last ditch effort to destroy it.
According to film producer J.J. Abrams, the creature is officially "...a baby. He's brand-new. He's confused, disoriented and irritable. And he's been down there in the water for thousands and thousands of years."
Originally posted by mandroids
Hmm, part 2....IT CAUSES EVEN MORE DESTRUCTION!!!! zzz