Novels where MC has both a humanoid form and non-human form BUT the non-human form is his true form and the human form is just a disguise. Looking for novels where this stays throughout rather than just a single arc. Doesn't matter if MC was originally human and became the monster or if it's a monster that became human. Examples for the former would be Way of the Devil and Legend of the Great Sage. Haven't really found any I recall from the latter(reincarnating from human and born as a monster then regaining human form isn't counted as I still consider that part of the former.) Doesn't really matter whether MC is male or female, as long as the novel is good and enjoyable. Requisites: -No Harem -No yaoi/BL/yuri
My Time as a Cat in College - MC has been ignorantly living as a (surprisingly long-living) kitten small cat but is one day informed that she's going to attend college for shapeshifters like her lol I haven't completed it yet (for reasons I can't remember but I put it in my return later reading list) and it's a slow paced story with romance Tensei Shitara Slime Datta Ken - I've only read the manga but there's a novel too. MC reincarnates as a slime in a fantasy world. He eventually gets a human form and does the whole town building thing.
Wow, all of these stories involve evil or at least anti-hero protagonists. But here you go. Most things by Haru no Hi. She mostly writes dark comedy/action/slice-of-life stories with female demon MCs who take on/possess human/humanoid forms. Her stories have a weird sense of humor that I personally love. She's also really good at capturing the mood of a monster horror from the perspective of the monster and making it entertaining. All of the MCs of her stories have human memories (usually from their past lives), but she has many side characters who are true demons wearing human disguises. Kumo Desu Ga: MC is reincarnated as a Spider, but eventually gets a human form. The anime is currently airing. The story does some really unique things I haven't seen in any other Isekai. The world building is pretty solid. Spoiler: spoiler It's eventually revealed that she was never human in the first place. Just a spider implanted with human memories and turned into a spider monster who eventually evolved into a humanoid form. Warlock of the Magus World: I'm not sure if this qualifies. The MC is human for about the first 10% of the story. Then he absorbs the blood of a Giant Kemoyin Serpent. At first this is just a bloodline thing giving him access to spells and advantages specific to Giant Kemoyin Serpents. As the story progresses, he becomes less human. By the end, his human and bloodline form (evolved from the Kemoyin serpent) are more or less interchangeable.
Have rad slime tensei but haven't heard of the cat one, looks interesting. I've read this but thx Werewolf novel isn't really the kind of novel I was looking for but thx anyway Re: monster has all the harem and polygamy stuff and I dropped it after reading the manga. Cthulhu gofalon is a novel I know of but nearly forgot, thx. I've read both kumo desu ka and WMW, while I have read one novel by haru no hi which I liked somewhat, I'll check out other novels by that author, thx.
Goblin Kingdom A Monster Who Levels Up Skeleton Knight, in Another World The Executed Sage Reincarnates as a Lich and Begins a War of Aggression Apotheosis of a Demon – A Monster Evolution Story My Entire Class Has Been Reincarnated – I Became the Weakest Skeleton!
Maybe Is that a Wisp? Protagonist is a wisp and his race is hunted, he becomes human with a cultivation method to hide that he is a wisp.
Not really looking for a kingdom building, so I'll leave out goblim kingdom. I have read Monster who levels up. I read skeleton knight before and dropped it due to finding it not my taste. I currently follow executed sage's manga and I'll just keep reading that. I have finished apotheosis of a demon. Last one is also not my taste. Too few chapters and also dropped, so might as well not read it. This looks interesting thx.