I like them a lot, but I must say these outfit items (chicken suit and more) are so common that players will end up with multiple sets of useless outfits as most of them aren't tradeable and have no value. To counter that you could possibly give the items some gp value, not at all something too much. I like the idea of multiple boxes and about the super mystery box, I would like to see maybe a chance of a high gp drop. I would also like to suggest a skilling mystery box that would countain various random skilling supplies ranging from high level to beginner level. I think it would be fun.