10 Years of the “Casper” Octopus

“Charismatic” isn’t usually the first word that comes to mind when you ask for someone’s thoughts on the deep ocean. “Fascinating,” sure. “Spooky?” Maybe. But in the darkness over 4 kilometers (2.5 miles) below the surface, charm is often the last thing people expect to find.

And yet, in 2016, the lights of remotely operated vehicle (ROV) Deep Discoverer revealed a deep-sea animal whose appeal would be hard for even the most jaded of hearts to deny. The ROV’s camera zoomed in on a small octopus, nearly translucent, resting on the seafloor. As deep-sea enthusiasts on social media reacted during the dive’s live stream, it became clear that this ghostlike octopod had been given a name by the community: “Casper.”

Discovering the “Casper” octopus was important for reasons beyond its inherent appeal. Deep-sea octopods are separated into two groups: “Cirrates,” like the famous “dumbo” octopuses, have fins on their bodies and fingerlike “cirri” associated with their suckers. “Incirrate” octopods are missing both of these features and look more like familiar shallow-water octopods. The Casper octopus’s discovery at 4,290 meters (14,000 feet) below the surface made it the deepest incirrate octopod ever found.

Explorers have spotted more octopods very similar to “Casper” in the 10 years since that original discovery. We’ve begun to learn more about how Casper octopuses may live and behave, too. Later in 2016, for example, a research team found two that seemed to be brooding their eggs on dead sponge stalks rising from the seabed— a meaningful discovery for our understanding of deep-sea habitats.

Despite these many sightings, the Casper octopus still has no scientific name. That’s because it’s very hard to judge where exactly an octopus like Casper belongs in the tree of life from photos and videos alone, and no specimen has ever been collected for scientists to study.

Ocean Exploration Trust spotted this Casper octopus during the Ala ʻAumoana Kai Uli in Papahānaumokuākea Marine National Monument expedition in 2023. The octopus was “walking” along the seafloor over 2,300 meters deep at ʻŌnūnui, ʻŌnūiki (Gardner Pinnacles), roughly 500 nautical miles northwest of Oʻahu. Video highlights of this octopus are available on the Nautilus Live website. Image copyright Ocean Exploration Trust, NOAA. Download largest version (jpg, 1.6 MB)

Much about the Casper octopus remains unknown, like the reason for its striking lack of pigment. Rather than fading from the spotlight, though, this little denizen of the deep has only continued to gain fans. In 2025, the original Casper octopus was the most-favorited animal in FathomVerse, a mobile game that lets players help identify ocean life.

“One cannot deny the cuteness of casper,” commented one FathomVerse player with the username “acanthogammarus” in a chatroom dedicated to the game. “It is scientifically impossible.”

There’s no telling when explorers might find another Casper octopus, or when scientists will take the next step in unraveling its mysteries. The ocean is a huge place, and each exploration dive only gives us a tiny glimpse of what’s out there. One thing’s for sure, though: Whenever and wherever this cute deep-sea dweller turns up next, its loyal fans will be there to cheer it on.