Wait I've never told y'all my hermit species headcanons! That's illegal and changes now (under cut bc its the entire ensemble)
Xisuma: Void Walker. There's a hard difference between the Void in the End and the Void under bedrock, and the latter is the one where Xisuma's from! Due to the intense pressure down there, they require a suit to navigate the otherworld - otherwise it'd be like a blobfish situation where their body just collapses in on itself
Hypno: Vemon. When people think of demons, they usually think of the nether, which is fair! But the nether is a reflection of the overworld, not the aether - that goes to the end. So true demons come from there too! But considering monsters in the nether already claimed that title, instead demons from the end are called Void demons, or Vemons for short. Hypno traditionally has a long, snake like form and struggles to maintain a human visage. Because of this, he wears lots of layers to keep his body pressed into shape. Additionally, he can use shadows as a navigation tool and teleports through them!
Joe Hills: Eldrich. When the new gods fought against the old ones, they tore their bodies apart and banished the pieces across thousands of worlds. Those fragments came to be known as the Eldrich. The are not bound by mortal or immortal rules, but arent powerful enough to retake their position in the holy order - not without finding their missing fragments, that is. Joe, personally, doesn't care about all that. He's having too much fun learning and building as any cerebrum would given form
Bdubs: Glare. Originally, Glares were hunted for their pelts and eyes as they were found to be extremely useful and desired in the markets. Once those had been hunted to near extinction, people went after the hybrids next. This lead to Bdubs hiding his species from most of the hermits until season 8
Keralis: Siren. Sirens don't typically leave their part of the sea, none the less the ocean entirely. But when Keralis found out his old pirate buddy Hypno was exploring the overworld, he wanted to come with! And if this rag-tag group was planning on housing people in danger, it might be wise to have someone who's really good at navigating social situations (ignoring the dubious methods as to how)
Cleo: Zombie. Listen, sometimes you use a little too much necromancy and, while technically can no longer die, you can still rot. Thankfully, there are plenty of spare parts
False: Human - Vessel of War. Gods have a hard time interacting with mortals in ways that doesn't lead to the mortals skin flaying off or sudden bouts of insanity. To overcome this issue, they will chose people and grant them powers so that they may spread their message and enact their will in the overworld. False was chosen by the god of war after her family was killed in a military assault, and she took the boon without hesitation. Technically human, but far more divine
Mumbo: Leviathan. As opportunist hunters, leviathans prey on anything that falls below bedrock. This has caused them to evolve a unique ability to syphon the life energy of these creatures to extend their own life. As Mumbo found out in season 8, in too much consumption, one can syphon more than just their life energy. Then again in season 10, he learned that by not eating, he ages faster than expected. Bit of a learning curve, but its not like leviathans have a parent to show them the ropes anyways
Tango: Phoenix. Death has always been a bit more of an inconvenience than a permanent state of self. Which is fine and all, just don't ask why Tango doesn't have those signature fire wings. He still hasn't told most of the hermits that himself
xB: Guardian. People who tell you guardians are machines have never met xB. Some machines have been fashioned after guardians, yes, but the animal came first. Now that his temple is unfortunately gone, he can go around making sure no one forgets that
Jevin: Slime. If you leave a monkey alone long enough, it'll gain sentience and call itself human. If you leave a slime alone long enough, it'll gain sentience and call itself Jevin
Doc: Creeper. Doc has lived a lot longer than any creeper physically should. This may or may not be due to a combination of his cybernetics and the eternal gift as given by a dying god to her last follower, but that's neither here nor there
Etho: Human - Shattered. Etho chased after immortality for so long that, while yes he did eventually find it, it did not come to him in a kind way. Science and magic helped extend his life, but didn't make it permanent. He made a few deals, but contracts can be broken pretty easily on both sides. Falling into the void didn't solve the problem, but that combined with the Jungle eating what parts remained of his soul has caused a spiritual turf battle. No other entities are allowed to kill him, and therefore he can no longer die except to the Void or the Jungle. So while he's technically human, no one would bother to call them that anymore
Impulse: Vemon. Same big explanation for Hypno but has a different primary form and powers. Impulse traditionally has a thick dragon body (think httyd gronckle), but is not a dragon. Can also chew through obsidian easily, and sometimes forgets he doesnt have to bite as hard while eating normal food. He owes several people new forks
Beef: Minotaur. What is a labyrinth without a minotaur? But, then again, a labyrinth exists as their prison, and would it really be fair to entrap someone who's innocent on all accounts? The Writers thought that maybe the prisoner deserved a chance at freedom and gladly granted it to him
Scar and Cub: Vex. Noted together because they were summoned by the same evoker. Summoning is a learning process, and the evoker never actually learned how to dismiss them back to wherever the vex originate from - much to the dismay of the other illagers, who now had to deal with two vex becoming conscious and breaking their bonds of servitude. The two were found in cages by the hermits when they were raiding the mansion, and at that point it would be nothing short of cruel to send them back. So now the hermits have to deal with two vex who have become conscious and broke their bonds of servitude (something they do happily, mind you, and wouldn't change for the world)
Ren: Werewolf. Unlike Etho, Ren was able to find a way to become immortal without the terrifying repercussions of never truly owning your soul*! Just bind it to some other guy who's also immortal and swear fealty to him! What, he's gone missing? Well, while you're looking for him is a great time to figure out the whole 'full moon shifting thing' so it kind of works out. *Bad news, they guy you've bound your soul with doesn't even own his soul. Don't think too hard about that, though
Wels: Human - Vessel of the Goddess. In the same sense of False, Wels was chosen under the Goddess of Wels. He doesn't have a name outside his title, the Knight of Wels, to avoid any name stealing contracts, but it's just easier to call him Wels for short at this point. He was chosen to act more like a proxy, an entity to fight against the forces of Hels where the two goddesses couldn't reach. Unlike False, however, he didn't have a choice
Zedaph: Eldrich. Same big explanation as given for Joe, but from a different old god. He's comprised of the hippocampus and amygdala, however, and has gotten too wrapped up in the learning and Shenanigans of hermitcraft to remember finding his missing fragments. Probably for the best
Grian: Fae, Watcher. So, technically by birthright, Grian was human. But, he was given to the fae at such a young age, and surrounded by such potent magic during pivotal development stages, he's basically a fae. To call him anything else would be incorrect at this point. And once the Watchers had sewn eyes into his very soul, he wasn't fully fae anymore either. It's a good thing they're pretty similar in terms of physiology in this case
Gem: Shapeshifter. It's no wonder Gem can adapt to any environment, whether its an enchanted forest or a haunted sea, with such ease. Do not be fooled by the fact that she often takes the form of prey animals, she can and will hunt for sport all while looking like a deer or butterfly. Season 10 was a dip into more predator aesthetics and Gem found she quite enjoys having fangs
Pearl: Fae. It's not often fae take on the appearance of humans, only done to trick mortals or outwit each other in dangerous ploys. But, they do tend to resemble the nature of things around them as a way to camouflage with their surrounding. Considering how long they live would land Pearl at an early enough age to develop human characteristics, but considering that not even the humans on hermitcraft look all that normal, her inherent wild nature continues to shine through in her patterns and antennae
Joel: Dryad. Not many peoples first though, upon seeing Joel, would be to assume he's a dryad. They can't go further than 50 meters away from their tree, so how could he possibly navigate through the seasons and expanses of the greater hermit area? Well, someone tried to burn his tree down a long time ago, and Joel had to quickly make a graft to save it. And now that the only part of his tree remaining is no bigger than a twig, it's quite easy for him to just carry it around with him. And, no, he's not sick or weak, thank you very much, he is totally healthy and doing just fine and could easily fight back with no problems whatsoever
Skizz: Angel. Not so much in the traditional sense but in the 'crafted to exclusively serve a god' sense. Skizz was created by the god of love as a gift to the god of war with the intent of acting as a jester of sorts. Someone who could distract their wrath and calm their rage while also being able to safely call them out on outrageous orders. While his duties ended up expanding to help mortals on the battlefield, not much about his personality changed. Skizz is currently 'on vacation' - its not his fault the hermits like to start civil wars, but he's excited about the chaos regardless