I just realized that there's no Dark-type bird of prey. I know that Mandibuzz and Yveltal(?) are vultures, and vultures are considered raptors, but they're scavengers, and a Dark-type raptor that plays on its aggressivenes towards its prey would be very nice. It could be something like a giant harpy/Philipline eagle or a hornbill (they're even black).

Post more ideas you'd like to see in future Gens.