Sea monsters terrorise Newgale beach
They are however completely harmless and are actually called goose or stalked barnacles.
This pic was sent in to our Flickr group by Aligail1:
Unlike most other types of barnacle which have small feeding arms known as 'cirri', they rely on the motion of the water to feed, so tend to be found only on exposed coasts throughout the temperate oceans of the world
They will often attach themselves to ships and clumps of driftwood and as such, do get washed in from time to time.
We had some similar scenes on Gower at Oxwich Bay earlier this year in August.
In some countries they're considered quite a delicacy to eat and believe it or not - were once thought to be birds rather than barnacles!
Their colouration is very similar to that of the barnacle goose (use your imagination) and since no-one had ever seen a barnacle goose hatching out in Britain...
People believed they came from these crustaceans and grew up on ship's hulls before developing feathers and flying away.
And why not? It makes perfect sense...
Why our very own Welsh monk, Geralt Gymro or Giraldus Cambrensis as he's known in Latin, also got involved and claimed to have seen goose barnacles turning into barnacle geese in the 12th century.
Clearly a man with a wicked sense of humour who lived a very exciting and colourful life.
If anyone else has similar tales or fables connected with other wildlife species, then I'd love to hear your stories - so please feel free to add your comments to this blog.
Goose barnacle article on ARKive
Goose barnacle on BBC Wildlife Finder