A dangerous Portuguese man-of-war has been found on a beach in north Devon.
The discovery was made on Sunday morning during a volunteers' beach clean at Westward Ho! for the Marine Conservation Society (MCS).
Stings from the jellyfish-like creature can cause severe pain and in very rare cases, death.
The MCS said there had been a recent increase in man-of-war reports, with sightings in Ireland, south Wales and several in Cornwall.
The creature, which looks like a jelly fish, but is actually made up of many tiny marine organisms behaving collectively as one animal, was found by Sallie Mckay Roper.
"It was stuck on a pebble and at first I just didn't know what it was," she told BBC News.
"It felt very much like plastic and with the bright colours I thought it might even be a deflating balloon.
"When we noticed the tentacles we took it back down to the water in case it might still be alive, but sadly it wasn't."
Ms McKay Roper, who led the beach clean in her role as a community champion for Tesco, said although she had heard about the Portuguese man-of-war, she had never seen one.
"It was quite exciting because it's so unusual... I'm just very glad I wasn't stung."
Dr Peter Richardson from the MCS said the number of reported cases had increased recently, which could be because of a "stranding event".
In the South West alone, there have been sightings at Portheras Cove, Summerleaze and Widemouth.
The Portuguese man-of-war normally lives in warm seas off Florida Keys, the Gulf of Mexico, Indian Ocean, Caribbean and Pacific, but winds and currents can bring it to UK water.
The tentacles pose the threat to humans, sometimes stretching up to 50m below the surface of the sea where the animals float.
Although there have been fatalities elsewhere in the world, Dr Richardson said no-one had been killed by Portuguese man-of-war stings in the UK.
Earlier this month 10-year-old Dawud Lee from Cornwall needed hospital treatment after being stung at a beach near his home in Penzance. He said if felt like a knife going into his foot.
The MCS has asked people who see the creatures to report them online, preferably with a picture.