The female Tauren tail rigging is more broken than ever and I have been reporting it often. In live, in alpha, and now in beta.
When she runs and walks the tail becomes hard and jagged. The Highmountain Tauren female’s tail is rigged perfectly, perhaps the weight painting can be copied from this model or it can be smoothed out on the current model.
Its weight painting is either jank or the vertices are too low.