this is an old video, but a therian is someone who identefies as one or more animals mentally or physiacly. Many of them has had a past life where they were that animal they identefy as. Not all therians had past lifes tho. Most therians do quadrobics (a sport where you walk, run and jump ect.) On all fours to feel connected to their animal. You can do quadrobics and wear gear (masks, tails ect) without being a therian. Otherkin is when someone is a therian, but instead of identefying as an animal, they identify as an mythical creature/dinosaur. (Non-human creatures) Otherhearted is very different but still gets confused with therians. Otherhearted pepole have a special connection to one or more animals.