I always thought that the Prune Faces looked like bad attempts to turn the Emperor Hologram from the OOT ESB into a wearable mask.

I'm all for putting them into the ground battle but the masks in the existing footage need a lot of Adywan style animating and any new shots of them need to be shot with more realistic looking faces.

They look like the sort of creatures who would have some sort of bizarre personal weapon like a laser boomerang or an oversized robot boomerang...some sort of boomerang would be a good idea.