Lifeguards are warning beachgoers that venomous Portuguese men o' war are washing up on three Phuket beaches and should be avoided.
The creatures were found on Nai Harn, Kata Noi and Kata beaches on Sunday.
Beachgoers should not touch them because their tentacles could still inject venom if touched, even after being washed ashore.
Their venom causes burning pain and severe allergic reactions, affecting the nervous system and heart function, though it is rarely lethal to humans.
Often mistaken for jellyfish, they are identified by translucent blue-purple balloon-like floats and can deliver an excruciating sting even when dead.
They typically float on the surface of warm subtropical and tropical oceans and may be blown ashore by winds and currents.
