On two separate occasions now I've put a fully evolved male pokemon into the Daycare with a Ditto, and had the offspring come out fully evolved. It isn't every male, obviously, and I've yet to figure out the actual trigger for the glitch, but once it's in effect, all eggs that come out hatch into the same, fully evolved pokemon as the non-Ditto parent. I can't be certain about the first time it happened, but in the case of the second, the eggs hatching as Hitmontop, they had four egg moves. If other people can replicate this, it might be possible to determine the trigger for the glitch.