Halloween // Help deciding a costume!

Hi halloweeners! So my son is 9, and turning 10 ON HALLOWEEN!!! He loves Halloween esp since it's his birthday too...

So we're stuck on Halloween costume ideas...

Hes got really light skin, blue eyes, and LONG blonde hair. I mean long...like it tucks into his pants waist...wanting to somehow incorporate his hair with his costume...

What's your best ideas? Wanna be unique, and definitely no superheroes...lol he wants to do something much more unique from other kids.

Give me your best!