The Buddy mob

You can use the posion of weakness and a golden apple to turn the zombie into the Buddy mob similar to the villager there are zombies in the ruin towns once you revive the Buddy mob will try to  rebulid the town the Buddy mob will be similar to the Player they will help when fighting other mobs they will also have variants they can also revive other Buddy mobs the Buddy mob will have stages of Zombification if it’s full zombified you can’t revive it’s mild you can revive them there  will also be blueprints so the Buddy mob can help you bulid