1 SPOILER ALERT!!!!!!
Believe it or not this is what the movie is actually about. Cloverfield is about a scientist who comes across a book known as MysticCreatures. Intrigued by this book, he goes off to Ireland to see if the place in the book actually exist. He comes upon the mystic Cloverfield and sees a Leprecaun. He captures this Leprecaun and brings it back to NewYork.
The Leprecaun befriends the scientist because he sees in the scientist that he has a good heart. The Leprecaun and scientist become sexual lovers, and the Leprecaun gets pregnant (btw, the Leprecaun is a female). The Leprecaun gives birth. The Leprecaun names the child CloverField from whence she came from.
The Leprecaun and the scientist gets killed by the US government because the US government doesn't want the cure of Hiv and Cancer to be known. Cloverfield escapes, becomes depress, do drugs for a little while, and becomes sick of all the ugliness of mankind,and she decides that mankind doesn't deserve to exist anymore; therefore, she transforms herself into .... the BEAST. Thus the name of the movie.... CLOVERFIELD.
