Let It Go belongs to Disney. The dragon species mentioned belongs to How to Train Your Dragon which is the property of Dreamworks.
I fly to lands unknown
my old home far behind
I played my part as the perfect
daughter of the chief (not)
I had been trying so hard to belong
but there's no place there for someone like me
Keep it secret, keep it hidden
Be the normal Viking you always had to be
Conceal, don't feel
Don't let them know
Well now, they know
Let it go, let it go
Can't hold it back anymore
Let it go, let it go
It's time for me to disappear
I don't care what they're going to say
Let the storm rage on
the cold never bother me anyway
For all those years I've kept
my powers locked up inside
and the fears that once controlled me
have flown away
Up here in the cold thin air
I finally can breath
I know I left a life behind
but I'm too relieved
to grieve
Let it go, let it go
My power pure and strong
Let it go, let it go
I will no longer live a lie
Here I stand
and here I belong
Let the storm rage on
My dragon flies through the air
far from the ground
My soul is spiraling
like the burn mark of a Typhoomerang
and one thought crystallizes
like a plasma blast
I've been holding back too long
To the past I'll say goodbye
Let it go, let it go
This Viking is reborn
Let it go, let it go
I'm embracing my true form
Here I stand
with nothing in my way
Let the storm rage on
The cold never bothered me anyway