Containment jars are fantastic and an excellent way to farm mobs... one extension to that to make it even more functional, would be the ability to give a Drygmy a particular item that could influence mob drops (drop an item nearby and they pick it up, right click with an empty hand to take it away, perhaps?)

The request would be, for instance, if the Drygmy could hold onto a Mystic Agriculture blade enchanted with Mystical Enlightenment, to generate Cognizant Dust when dancing around a Wither/Ender Dragon. Or holding a purpur knife to generate dragon teeth.

A complication to this... give a Drygmy a bucket with a cow in a containment jar... Bucket is filled, then put into the chest. Instead of using durability, would need something like a filter, I suppose.

Thank you, would love to see this idea implemented if just to see a whole herd of Drygmys all dancing around a bunch of cows. :)