Vidmaster Challenge: Annual

Vidmaster Challenge: Annual is a new achievement where you have to complete Halo after 9/25/08 on Legendary Co-Op with four players, Iron skull, and everyone in Type-32 Rapid Assault Vehicles .

It has been announced that while the Vidmaster achievements do not give you any points, they are worthwile for some mysterious prize when you get all off them, although this cannot be accomplished until the Mythic Map Pack is released.