It has been said for a long time that druids need some love, particularly in the form of a charmy. Currently they have access to conjure elemental which is not entirely useless, but the vast majority of charm stones are crap, and on top of this the spell destroys the stones. The good ones are not easy to get.
How about a higher tier of stones being loadable on high level Druid mobs and these stones can be attuned as per rings recently introduced. After you cast conjure on the stone it disappears but when the elemental is destroyed the stone reappears on the ground. If you release the elemental it reappears in your inventory.
I am not envisioning a trainable pet such as mages, but more akin to gate, with useful skills.