Unidan, AKA Ben Eisenkop, is an ecosystem ecologist who first rose to fame (infamy?) on Reddit by popping up in posts across the site, answering any queries and concepts pertaining to biology and ecology. Eisenkop is a columnist for Upvoted, where he spotlights a new creature every week.

Have you ever been swimming in the ocean and thought, “this water isn’t nearly slimy enough for me?”

We’ve got you covered.

Today’s bizarre beasts are the hagfish (class Myxini), a group of marine fish that, well, aren’t easily defined. Hagfish, while often referred to as “slime eels,” are not actually eels.

Hagfish are vertebrates, as you’d expect from a fish. However, while they possess a skull, they don’t have a vertebral column. Vertebrates, no vertebrae. Let’s just move on, shall we?

In many respects, they’re similar to lampreys, which more people are familiar with, in that they are jawless and like to chomp (well, rasp) onto things. Hagfish can often be found ripping apart dead or dying sea life, and they’re quite adapted to it! It has been theorized that hagfish may even have the ability to even eat through their skin in some respect, allowing some passive intake. This comes in very handy as hagfish have lots of skin-to-meat contact as they often wiggle their way inside of their meals, sometimes eating still alive animals from the inside out! Here’s a video of countless hagfish feeding on a dead whale courtesy of the BBC:

Should the hagfish be targeted by a predator, it has a very unique trick of up its sleeve: slime. When agitated, a hagfish releases large amounts of a microfiber-containing mucous which then combines with the surrounding water to create even larger amounts of slime, sometimes over five gallons per hagfish in a single encounter! This slime is theorized to cover and entangle the gills of predators, essentially suffocating them should they attempt to pursue the hagfish. The hagfish, meanwhile, works itself into a knot to peel the slime off of its own body. Here’s a video of the sticky situation courtesy of the Vancouver Aquarium:

Interestingly, hagfish are of commercial use to humans! While some countries eat them as a delicacy, many others use them for a purpose many would not guess.

Have you ever seen a wallet or a belt marked as “eel skin leather”? If so, know that your wallet used to be much slimier, even before you put your driver’s license in it.