The rarity of Waaagh Big 'Un is Rare, and been equipped it takes a “Bundle” slot. At this moment the item is available for trade.
Waaagh Big 'Un is a skin for Alchemist. The skin was added to the game on September 1, 2016, it was created by katzeimsack.
Waaagh Big 'Un has been recently added to the game, which makes it rather popular with the game community.