The box jellyfish is already one of the deadliest creatures on Earth. Mother Nature decided we needed another one.

According to research published in the Raffles Bulletin of Zoology, scientists from Tohoku University and the National University of Singapore have identified an entirely new species of box jellyfish floating like a carelessly discarded plastic grocery bag in the waters around Singapore. The newly discovered species, named Chironex blakangmati, belongs to the same genus as the terrifying gelatinous killers already floating around out there, packed with a potent venom that can trigger heart failure and nervous system collapse in an unlucky swimmer.

Researchers collected the jellyfish near Sentosa Island. It wasn’t always called that, though. Historically, its name is “Pulau Blakang Mati,” which roughly translates to “the island behind which lies death.” Of course, that’s where scientists would find a new species of murder jellyfish. Was King Kong discovered in some place called Pleasantville? No, he was found on Skull Island.

Box Jellyfish Are More Sophisticated Than They Look

When they first saw it, the researchers thought it looked just like another jellyfish species, the Chironex yamaguchii. Genetic testing revealed that it was a completely different species, but with a key physical distinction involving a set of structures called the perradial lappets. Those are muscular flaps that help propel them through water. The researchers knew something was up when this one lacked pointed canals extending from those structures.

It’s a minor detail, but one that matters quite a bit when you’re trying to distinguish one type of jellyfish from another. Box jellyfish don’t just float there, inert, allowing the ocean currents to take them wherever. They actively hunt prey with an advanced set of eyes and muscular control.

Researchers also documented the first appearance in Singapore of another dangerous species, Chironex indrasaksajiae, which, previously, was mostly seen hanging out in Thai waters. Tracking that range expansion is important because we still don’t know much about where box jellyfish live or the routes along which they migrate, all stuff that we should probably learn about, considering a box jellyfish sting can kill a person in less than five minutes.