We all know that villagers can turn into zombies. So why not the opposite? How about a rare villager that appears in only a few villages and can heal tamed mobs, Villager Zombies, and heck, even players! Oh, and when I said they can heal villager zombies I meant that they can convert them back to villagers. I think this would be a really awesome addition to the game. And you could also give them a trade function; trade emeralds for healing potions. I hope you like this idea!