I know i am being a bit on the sarcastic site here but i just cannot help it with this.
So i created my Druid, took the Moon route since i like the transformations, especially since i read something about elementals...
So when i got my second set of Wild shapes i get a Raven, nice and....a Cave Cow :O
whoever got the idea that i want to transform into a cow? Even if it's the underdark version, it's still mostly a farm animal there. That's for my personal opinion, i am sure there are others.
My main issue is, that Drow would be the only druid who would even think about that transformation. Maybe Duergar or Svirfneblin.
For Druids living in the sunlit world that is a bit far fetched. IF someone would consider a shape out of the underdark i guess it would be a more useful one (well, can female druids give milk?)
Maybe a displacer beast or hook horror. A Deep rothe is imo not really fitting.