Jeweller Mark Evans from Market Harborough, Leics, saw it while he was out walking his dog this morning.
Mr Evans, a regular visitor to north Norfolk, said he had never seen anything like it.
'It appeared to be some sort of jellyfish at first sight,' he said. 'I saw it while I was walking my dog, there were two of them.
'As you can imagine, there are lots of things you see washed up on the seashore. I go to Holkham quite a lot but I've never seen anything like it.'
We've passed the image on to the Norfolk Wildlife Trust to get an expert opinion.
If you can identify the creature in the meantime, leave a comment below.
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