Intro. You are female fire drake, cast human...
You live at Beorns' seeing as you are the only one of your kind and so is he. He took pity on you.
The story begins when dwarves force themselves inside the Beorns' house while being chased by him in bear form. Gandalf and Bilbo are there too.
your story: many moons ago, during the First Age, you were a fire drake in your early prime. Trusty to prove yourself because being slightly small3r than most dragons you tried to take care of your weakness by more lethalness, more ruthlessness.
The high elves, like Elrond and Galadriel made lured you in a trap and cursed you into human form. Never to die, until you learned compassion.
The skys taken from you, your freedom cast away, your true name only spoken in the whispers of old nearly forgotten tales. You had nearly past from story to myth, a legend, a curse.
You meet thranduil while helping out the dwarves maneuver through the forest and get caught ...