He is a humanoid/spider like alien with six limbs and has secondary eyelids that covers his real ones, with dark green/grey and white skin.
In late 1958, his ship crash landed on earth. Cooper was then captured by the military and was experimented on by local scientist, Dr. Thomas Woodward. in 1979, he was being transported on a train to some other base, but when Woodward stopped it by driving a truck into the train, which freed Cooper as he escaped in town.
After escaping, Cooper takes shelter underground above the town water tower, also he began collecting auto parts and whatever else he could find, as well as captured humans and used them for food.