A woman and her son were shocked to find mysterious creatures, resembling an eyeball, washed up on the shore of Mustang Island in Texas.

Jennifer Baltazar noticed the creatures only after her son complained of a stinging pain in his foot. Baltazar told media outlet My San Antonio she saw the jellyfish-like species and took pictures of it.

She then sent the images to Mission Aransas reserve director Jace Tunnell at the University of Texas Marine Science Institute to know what the creatures were.

Tunnell told My San Antonio he had never seen the creatures before.

"I've never seen these things wash up before," Tunnell said. "... Certain times of the year these jellyfish and stuff fluctuate coming in, and we randomly find interesting things coming, and this one, in particular, kind of threw me off ... it's an interesting find for sure."

Baltazar found the creatures on March 29, but they were identified Wednesday. It was revealed the weird creatures were Rhizophysa eysenhardti – a species related to Portuguese man-of-war.

Mustang Island State Park shared images of the rare creature on its Facebook account, saying these are also called spaghetti monsters or thread-jellies. The park said the creatures are native to the tropical Atlantic and Indian oceans, which is why they are rarely seen in the Gulf of Mexico.

Tunnell told My San Antonio the sting of these creatures is not as strong as that of Portuguese man-of-war, which are known for its powerful sting. However, he suggested it's best to leave them alone.

"Take pictures but leave the animal there," Tunnell said.

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Mysterious and bizarre-looking sea creatures often wash up on beaches, baffling locals and, sometimes, even experts about its origin.

Recently, a jellyfish-like creature washed up on the shores of a beach in Scotland, leaving locals concerned about its identity. The creature was first spotted by Caroline Lennon, an East Lothian local. "I’ve found a few things on the tide line over the years but never found one of those before!" Lennon told the Edinburgh Live about the creature she found on Gullane beach. After the images surfaced online, many users took their guesses as to what it could be. One social media user asked Lennon: "Is the blue bit shell?" She answered saying that: "No, it's squashy like a jellyfish but maybe a bit spongier... Yup, we're feeling a bit unsettled too." It was later revealed the creature was a sea anemone that had turned itself inside out or had flipped over.

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Representational image AFPTV / Jonathan KLEIN