The Soldier Costume Transmogrifier, added in the Halloween update of 2013, had a bucket included in its backpack icon, which all other class Transmogrifiers lacked. This was an early reference to the Team Foretress 2 short animation, "Expiration Date", released in June of 2014, and the Soldier's obsession with a similar looking bucket in the animation.
Contributed by tomp45673
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