A newly discovered carnivorous caterpillar on the Hawaiian island of Oahu has earned the nickname “bone collector” for its eerie habit of wearing the remains of its prey. This unique insect prowls along spiderwebs, feeding on insects caught in the web and using their body parts—like ant heads and fly wings—to decorate its silk case.

While Hawaii is home to several caterpillars that build protective cases from natural materials like lichen and sand, this is the first known to use the body parts of other insects. “Carnivorous caterpillars already do some wild things, but this one really stands out,” said Dan Rubinoff, a researcher at the University of Hawaii at Manoa.

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Scientists believe the bizarre decoration may serve as camouflage, helping the caterpillar avoid detection by the spiders whose webs it raids. The research, published Thursday in Science, reveals that these caterpillars are extremely rare—only 62 have been spotted in over two decades of fieldwork.

Not only do these caterpillars feed on other insects, but they are also cannibalistic, sometimes turning on each other. Their lineage dates back over 6 million years, predating the Hawaiian islands themselves. Today, they cling to survival in a remote mountain forest, threatened by invasive species and habitat loss.

“This discovery highlights the urgent need for stronger conservation efforts,” Rubinoff emphasized.