The rarity of Aspect of the Year Beast is Rare, and been equipped it takes a “Bundle” slot. At this moment the item is available for trade.
Aspect of the Year Beast is a skin for Wraith King. The skin was added to the game on February 24, 2015, it was created by DotaFX.
Aspect of the Year Beast has been recently added to the game, which makes it rather popular with the game community.