The Hoarder is an entity formed through symbiosis between a store mannequin and a supermarket shopping cart under the influence of Stardust, wandering around picking up unclaimed items. - There is no such thing as trash, only items that appear in the wrong place!
It seems to retain its hoarding obsession from when it was alive. Every 3 to 5 of them build a shared "nest" to stockpile the supplies they collect. If anyone approaches or takes its collections, the Hoarder erupts into a rage utterly disproportionate to its appearance and pursues them relentlessly.