Goats can spawn in the plains biome. They can be sheared for goat fur or milked for goat milk. Goat fur can be crafted into Goat Armor which gives you Regeneration when you are wearing the full set. Goat milk can be crafted into goat cheese in the crafting table.
Hitting a goat with a ritual knife while it is standing in the middle of that summoning structure will turn the goat into a bloody goat. Bloody goats will drop bloody goat fur when they are sheared, but they will not grow their fur back.
Ritual Knife Crafting Recipe
Ritual Orb Crafting Recipe
Right clicking with a Ritual Orb will summon the Goat Boss. If you defeat it, you will receive a Goat Sword. Defeating it will not be an easy task. Good luck!
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