A new potion: the Potion of the Undeath

A brand new potion made with rotten flesh that gives you all the capacities of undead mobs:

- You burn at daylight;

- Undead mobs will be neutral, except the Wither;

- Effects from Instant Damage and Poison will switch up with Heal and Regeneration.

Also, while in this state, Witches will throw regeneration potions instead of poison potion!