You are going to need a lot of blocks for this build so you should better get to farming. As for the blocks themselves, you can pretty much use anything. Cobblestone and Wood are the most common ...
aCookieGod on MSN
I built an insane mob spawner farm in Minecraft hardcore
So I built one of the most INSANE mob spawner farms to dominate the game. The risk was huge… but the rewards were even bigger.
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