Kinky. But for real, some races can interbreed with other creatures. Beastmen can interbreed with humas and farm animals. The offspring will always be a Beastman. In old Warhammer lore it was mentioned that every once in a while, a group of drunk Beastmen would come out of the woods and try too get some cow/goat/sheep/horse tail. Beastmen are especially hated by farmers. Skaven can also breed with human women, but in a weird way. The Skaven would have too turn the woman into a broodmare, a horribly obese and mindless monstrosity, indistinguishable from a regular Skaven female. This process is very long and has a low rate of succes, so it doesn't happen very often. Daemons can also do it, but the child will either be a complete daemon or a horrible halvbreed abomination.