How do I heal my Mo'Creatures ghost Wyvern?

I made a sea wyvern farm with mo'creatures, but one of them suffocated in a wall. It became a ghost wyvern, but it's damaged because of the suffocation. A potion of healing damages it (like it damages all other undead) and I don't want to kill him as a ghost. How do I heal him without using potions of healing?


Solution 1:

Undead creatures can be healed by using Potions of Harming on them.