She was an Mightyena, but after a strange comet hit earth, she (alongside many other pokemons) became human, and fled from her house. [Be male or female, and it's your choise wherever you were her trainer or not, and if she recognizes you in case you were her trainer]

They're both from pokemon: sun and moon. STORY: You were a trainer, with an ancient amulet called "The beast clock", wich cluld make anyone who looks at it swinging succumb to his primal need, and tested it on them...