Australium weapons are not a very rare classification of weapons introduced in the Two Cities Update. Similarly to Botkiller weapons, they are unique reskins of specific weapons, and are awarded upon completing a full Tour of Duty in Mann vs. Machine mode. Unlike Botkiller weapons, they are only awarded upon completing a operation gear grinder, operation mecha engine, operation two cities or operation steel trap Tour. Australium weapons are always strange with a random tier of killstreak and the only enemies that actually have a australium corpse from death from these weapons is from the Saxxy or the golden frying pan, other deaths are normal.