I've just gotten to the desert levels in Castle Crashers yesterday.
In the very first level, you get to pick up a shovel which you can use to dig up various things buried in the sand (marked by small black Xs on the floor). One of the things I managed to dig up looked sort of like a black boot with green laces (I'd describe it better, but I have no idea what it is, exactly. It's more than possible that it isn't a boot at all, perhaps a some sort of armor?). Once I walked over it to pick it up it simply disappeared with no apparent effect.
So my question is, what is the purpose of this mysterious item?