halucinations

I think that there should be halucinations to make things VERY interesting, they can be like when you don't sleep for about 2 or more nights you start to see mobs and blocks very differently. Say there is a creeper next to you but you see it as a cow or pig so you don't see it as a creeper but it still acts and sounds like one, and say you are mining and then you see emerald ore in front of you so you mine it only to get coal! This should be an option to whether you want it or not hope you like this idea!