Seroquel uk sales Although I didn’t intend on dressing up as Finn for Halloween, after I made the Finn hat, I just couldn’t stop. I mean, what’s a Finn hat without a handy Finn backpack? This minimal costume/cosplay was fun to make, fun to wear, and I can’t wait to wear it to my next con! With that, here’s a lengthy tutorial on how to make your own Finn backpack.