Board Thread:General Discussion/@comment-24768935-20140624042149/@comment-29602226-20170627174832

Kenkou Cross has confirmed that Devil Bugs and Large Mouses are the most common Mamono breeds.

Besides that, I think the most common breeds are Succubi (default monsterization of women when a land becomes corrupted by DE, when they eat corrupted food, when they are cursed...etc.), Nereids (all woman who drown become Nereid, plus Nereids actively attack and turn into Nereids all women they meet), Zombies (female corpses in Demon Realms tend to rise as such), Matangos and Ropers (both kinds can spread quickly, turning whole countries into Demon Realms...).