Short for therianthrope
a therian is somebody who feels a connection with an animal. Not necessarily an animal from this plane either, although most accepted therians tend to be animals such as wolves or big cats there are some who believe themselves to be unicorns or other mythical creatures.
The connection the person feels with the animal can range from feeling they have been born into the wrong body (similar to those with gender issues) to simply a belief that they were an animal in a past life and still retain some memories or behaviours of said animal.
Therians do not physically become the animal they have a connection with, although some do describe "mental shifts" where they feel their whole thought process becomes that of the animals.
Therians are not to be confused with the Furry fandom who have a completely different relationship with animals.....
Her therian nature came to the fore.