The explanation in the MM3 for how redcaps reproduce (budding?) is dumb, and so my sick, twisted mind conceived something else. Now, for a little frame of reference, my world is full of trolls that kidnap and rape human women to produce magic-wielding hags for their clans, so this shouldn't be too out of the "ordinary" for a gritty Viking world.
Since redcaps enhance their life force with the blood of corpses (or require the blood to sustain their lives, as in the legend redcaps are based on), I thought that blood and corpses should have something to do with their reproduction. I had the idea of an elder redcap having the ability to detect (presumably via pheromones) if a woman is in the early stages of pregnancy, and after slaying her, rapes her corpse. His seed then "infects" the child, and it continues to change and grow in the rotting, swollen corpse, until a new redcap claws it's way out of the poor woman's putrid flesh. It then rips a patch of cloth from her garments, soaking up the bloody remnants of her womb, and places its new bloody cap on its head.
So, thoughts?