A spider chicken should not exist in Minecraft. I mean, just saying the words "spider chicken" sounds wrong. But, because of a mad scientist villager intent on creating chimera mobs, he does exist.
Listen to this first book in the Diary of a Spider Chicken Series to find out how the spider chicken came to be and what he plans to do about it.
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This is NOT AN OFFICIAL MINECRAFT BOOK. NOT APPROVED BY OR ASSOCIATED WITH MOJANG.