Crop circle expert Karen Alexander said: "We have seen butterfly and bird patterns in the past, but this is the first jellyfish crop circle in the world.
"It is absolutely huge - roughly three times the size of most crop patterns and extremely interesting. People have been aghast at the size of it. It is a complete monster.
"We are looking into the meaning of it, but at present it just seems to have appeared out of nowhere."
The owners of the land say whoever created the design caused about £600 of damage - but they called the shape "beautiful" and say they have reported the trespassers to the police.