Skull Balloon: an epic cosmetic worn as a balloon, from the Halloween edition.

The edition is over: merchants don't sell it any more. Whoever has it keeps it, and can sell it as a token at the auction house.

You can recolour it from the wardrobe: right-click the cosmetic, pick one of 63 colours and click the preview. It's free and you can change it whenever you like.

The token

In the wardrobe, Shift + click twice on a cosmetic you bought and it becomes a token in your inventory: sell it at the auction house or trade it. Right-click with the token in hand and the cosmetic goes back to the wardrobe.

From the same edition

HeadWendigo Helmet

From the northern woods, hunger grew antlers.

Can be recolouredOut of editionHeadPlague Mask

House calls, nights only.

Can be recolouredOut of editionBackWendigo Coffin

Better not ask what's inside.

Can be recolouredOut of editionBackPlague Cage

Two glowing eyes, and nobody has the key.

Can be recolouredOut of editionOff-handWendigo Axe

Nobody remembers what it cut, and that's for the best.

Can be recolouredOut of editionOff-handPlague Lantern

It lights the road, not where it leads.

Can be recolouredOut of edition