Who are they?

On August 21, 1955 at Sutton's Farm, Hopkinsville, Kentucky, strange small green shiny creatures surrounded the farm. The Suttons shot at them but the bullet did nothing, it merely made the creature stumble. The police arrived but the "goblins" (as they were dubbed) weren't found. When the police left, the "goblins" returned but eventually they left again. This was the first documented close encounter with aliens, although it wasn't thought of that at the time.
People were then claiming encounters frequently after this event, from seeing shadowy figures in the night to being abducted and probed. Many of these accounts have evidence to back them up. One such account was where a man saw a silver-suited spaceman and took a picture of the creature. Another encounter was where a man saw two creatures next to an egg-shaped craft. After the craft took off there were marks in the ground where the legs had been. There are also the encounters where there is no evidence to back up the claim.
When people say they have seen aliens there is almost always a picture of a humanoid with no hair and large eyes. Sometimes the aliens have large heads, green skin, gray skin, or are short like 3-4 feet tall. Every once in awhile the descriptions vary from the usual sense, like when a man claimed to encounter one-legged robot like, elephant armed creatures that abducted him. The true form of aliens is unknown or even if we knew an alien who's to say that it is the only ones we have encountered.