I've started the 30 Day Monster Girl Challenge
(link moderately NSFW), but using Sailor Moon MoTD as bases for the designs. Some of them will change the MoTD to fit the mythology, and others will change the archetype to fit the MoTD. Hopefully both should still remain recognisable.#1: Harpy
But of course we start off with a monster that's never been featured in Sailor Moon... I picked Vena, who had wings in the original, and made her a full harpy. I really liked her design in SM. The mysterious gold floating shoulder... thing is particularly interesting. She looks very mystical and a little religious, as though she's some evil priestess. At least, to me.