In Mojangs snapshot 12w38a they have released a hostile mob which is not yet spawnable (only by spawn egg) and a Neutral. Two both being scary-like creatures based around Halloween. With Halloween coming soon i have a strong feeling the patch will be available around Halloween time. The bat is a flying mob which is neutral, the collision box is smaller than that of a silverfish. Bats currently have no drops. Witches on the othr hand will be quite rare just like villagers. I believe they will situate themselves in a hut with cauldrons, a brewing stand and brewery based loot. The witch is currently a villager in a witches hat and a purple robe. They automatically attack with a splash potion of poison which causes 30 seconds of poison damage. They are prone to there own attacks which is fortunate.
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