Meet the nudibranch, a type of sea slug—soft-bodied, colorful, and oh-so-freaking adorable. Don’t be fooled by their cute, rainbow exterior, though. Nudibranchs are just as strange and freakily salacious as their name implies.

Even though they may seem alien, you can find them all over the globe. These mollusks inhabit every ocean from arctic to tropic seas. Some even live in hydrothermal vents at the bottom of our oceans.

Though most of these little guys are barely an inch long, some can grow to over a foot long. (I find the idea of large ones just as cute, but I think I may be in the minority.)

Unfortunately, these ocean-dwellers live a very short life—often not surviving for more than a few months to a year. That doesn’t mean their lives are not full of adventure, however!

“This probably varies with the species, and their habitat, but no one knows [how long they live] for sure. There is no way to tell their age based on their size and it is very difficult to keep most species in captivity for very long,” Cal Poly Pomona sea slug biologist Ángel Valdés, Ph.D., tells Upvoted.

Unlike their drab, slimy, cousins, the snail, Nudibranchs don’t have hard shells to protect themselves from hungry predators. Though you shouldn’t be mistaken—nudibranchs are anything but easy prey for the picking. Evolution has made sure that they will not be bullied by bigger creatures so easily.

“Most scientists think the bright coloration of many species is a warning to potential predators that the sea slugs are toxic,” says Valdés. (Although some species only come out at night, so their colors are never visible, he adds. Deep sea species might even be white in color.)

Now, here’s where things start to get a little… strange. Though we’re not at the freaky part yet, so you can keep reading if you have a weak stomach.

Toxic

Nudibranchs are strictly carnivores (surprising, right?). They don’t care for algae or other boring plants. Instead, their culinary tastes can only be described as brave, I suppose. Their dietary preference? Poisonous, killer creatures. That’s right. They have a taste for poison!

When devouring poisonous sea sponges or sea anemone stingers, nudibranchs absorb the toxins in their bodies. Instead of dying, they actually become toxic themselves. An ingenious and admirable survival method, if I do say so myself.

“Some nudibranchs contain compounds that are toxic to people. For example, phyllidiid nudibranchs have chemicals with a cyanide group and are probably very toxic, but the toxicity to humans of most species has not been tested,” Valdés explains.

Nudibranchs are hermaphrodites

Fun fact: Nudibranchs have both a penis and a vagina. Of course, this isn’t unusual in itself. Tons of creatures are hermaphrodites—some may even say it’s quite normal in the animal kingdom.

Now, here comes the fun part. Are you ready? OK.

In 2012, researchers were observing the mating habits of nudibranchs. For science.

They discovered that a peculiar species of nudibranch, called Goniobranchus reticulata, severs their own penises after copulation. Yep—they cut off their members (hopefully the sex was worth it to go through such extreme measures).

As if whether or not they are mutilated forever? Don’t worry, their detachable penises can grow back within 24 hours.

“No other animal is known to repeatedly copulate using such ‘disposable penes,’” writes the researchers in a 2013 study published in journal Biology Letters. (You can imagine the researchers writing that statement with glee).

In case you’re curious to see what nudibranch sex looks like, the authors of the study shared this close-up (you can thank me later):

As one Reddit user describes (though to be fair, the user hadn’t seen yet seen any pictures of copulation):

And as one user puts it: