The polymorphic wand uses the latent energy available in Blazegold to activate the Polymorphic Fluid, randomly changing mobs from one form to another!
Simply activate the wand on a hostile entity, and it'll convert randomly into another hostile entity. The same can happen with peaceful entities.
With this simple form of the wand, it is not possible to guarantee which mob you will get, nor is is possible to swap hostile and friendly mobs with each other. You suspect the wand can be upgraded to allow for these features, however!
