I like the idea for the most part as it adds something to the game and for people who are interested to farm for as its purely cosmetic (reminds me most of the different colour bamboo hats) However in the example for a shiny scorpion tail or bear paw, what purpose does it have? as those are just mob drops and can't be used cosmetically, will they have an increased sell value? or maybe the shiny mob drops could serve another purpose?. Would like to see what ideas you guys come up with.