Experts have warned beachgoers in Texas to not touch creatures reminiscent of 'your worst nightmares.'

The creatures, known as fireworms, are six to 12 inches long and have a sting that can make humans feel like their skin is on fire for hours.

Their dark brown bodies have neurotoxin-filled bristles that break off when they come into contact with human skin and inject a poison that can also cause dizziness and nausea.

Researchers reported that several fireworms were found on barnacle logs that washed up on Mustang Island and Padre Island near Corpus Christi. 

Fireworms are typically found in the Gulf, Atlantic Ocean and the Mediterranean, and researchers report are warning beachgoers to keep their distance.

'The reason it's called a fireworm is because when it stings you it feels like fire,' said Jace Tunnell, director of community engagement at the Harte Research Institute.

'If you touch it, it can get stuck in your skin very easily and it causes massive pain for about three hours.' 

There are 28 types of fireworms found worldwide, but the at the Harte Research Institute for Gulf of Mexico Studies identified the fireworms found in Texas as amphinome rostrata due to their dark brown bodies, small heads and little antennae.

These creatures can live up to nine years and although they aren't typically aggressive, they use their poisoned bristles as a defense mechanism when they feel threatened.

Although their sting won't hospitalize or kill you, it can induce dizziness, nausea and fever, and leaves a red mark at the site that won't fade for several weeks.

'I've seen videos where people have gotten stung before and even a month later, there will still be red marks,' Tunnell told Pen News.

The population size of fireworms in the Gulf remains unknown due to a lack of research on the species.

'These creatures can be found around the world, especially since they float on debris in the ocean currents.

'We've had lots of debris washing up over the past few weeks with gooseneck barnacles, which is their main food source. 

'So our guess is that they are just showing up because of ocean currents and winds bringing them up on the debris they are riding on.'

It can be difficult to find fireworms if people aren't searching for them, according to Tunnell who said: 'Our hope is that by letting folks know that these worms are washing in, they will know what to look for and can tell others.'

Beachgoers should carry duct tape to pull the bristle out if they're stung and clean the area with a mixture of vinegar and warm water to ease the burning sensation.

They can reproduce asexually, splitting their bodies into two or more parts and regenerating the heads or tails into fully-grown fireworms.

The creatures can also reproduce through regular mating which typically occurs between two to five days after the full moon. 

Tunnell advised people to avoid touching the fireworms but suggested observing them in water.

'They are such a cool-looking creature if you can put them in water,' he said, adding: 'I suggest taking photos and then releasing them back into the ocean.'