Unicorns may not be scientifically proven—but the unicornfish is legit! There are around 20 species of unicornfish, also known as unicorn tangs, that make up the genus Naso. While they’re named for the horn-like structure on their foreheads, not each species has horns—and the purpose of the appendage is still a mystery. That’s not their only bodily accessory, either. They also have sharp blades on their tails that come in handy when warding off foes. These fish live in tropical reefs in Indo-Pacific waters, where they swim in schools and snack on zooplankton.
Photo: zsispeo, CC BY-NC-SA 2.0, flickr; Bluespine unicornfish (Naso unicornis) pictured