This is my Original Species: Spectriums! First created as a one off character that has since expanded into an entire culture and D&D homebrew race, Spectriums are an alien race with the ability to shapeshift into a Serpent form (image 3 above) after much experience and training. Culturally they are divided into 1 of the 3 working classes: Phrenos (the artists, scientists, philosophers, scholars), Valios (the guardians, soldiers, warriors), and the Cenos (the craftsmen, labourers, farmers). In terms of sex, gender, and attraction, Spectriums would most commonly be labeled as the human equivalents of Intersex, Genderfluid, and Pansexual (and frequently Polyamorous) on average. This is mainly do to their trait of being able to reproduce with any two individuals (much like snails), were both have the organs to impregnate and birth offspring simultaneously, such that either can be both "mother" and "father".
There's a lot more lore and characteristics I've made for them, this is just the tip of the iceberg so far! But on that note, I am trying to create more lore for them, so I am actively seeking prompts, questions, and thought experiences to make them more fleshed out, so please feel free to message or ask me anything about them!