The 600ft monster, similar to a giant Portuguese man-of-war, has delighted crop circle watchers by turning up near Kingstone Coombes, Oxfordshire.
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, three times the size of most patterns.
'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.
Sceptics might suggest that someone in Oxfordshire is trying to muscle in on Wiltshire's dominance in the crop circle stakes - from April to the September harvest the mystery patterns are believed to bring millions of pounds in tourism to the western county.
The massive jellyfish thoroughly trounces the 350ft Wiltshire yin-yang symbol mysteriously cut last week into a barley field near Devizes, a crop circle hot spot. The design is not strictly a circle, of course, and is a long way from the simple shapes that appeared in the 1980s and gave rise to the name 'crop circle'.
Some argue that the patterns are the work of artists with access to computers and plenty of volunteers - but crop circle enthusiasts say summer nights are just too short to accomplish such complex work secretly.
Source: dailymail