Several dangerous Portuguese man o' war "jellyfish" have been found washed up on a beach in Cornwall, UK.

The creatures were seen on a beach near Perranporth on Tuesday (September 12).

Their venomous tentacles can deliver a painful sting, which can be fatal.

These floating hydrozoans use an air sack as a sail to drift around the sea.

Despite their appearance and reputation for stinging, technically they are not jellyfish but siphonophores.

Several dangerous Portuguese man o' war "jellyfish" have been found washed up on a beach in Cornwall, UK.

Cornish beach goers and their dogs investigate the strange alien-like objects swept ashore by Storm Aileen. The tentacles of the Portuguese Man O'War are very painful and can be fatal to humans. Consequently local vets are asking dog walkers to keep their pets away from these beautiful sea creatures.