Well, this is a crossover I never expected.
Realistically, I don't think any mamono would be a hogwarts student, both because only human wizards (or occasionally half-giant wizards) are allowed as students, and because they use magic under a completely different system, using mamono mana and sex, likely making Hogwarts corriculum useless to them.
That said, if they're was a Mamono school that used a house system similar to Hogwarts, I'm thinking something like:
Gryffandor: Proud warrior types, like Orcs, Hinezumi, Lizardfolk, Salamanders, Ochimusha, valkyrie etc. (also Jinkos, and Ocelomeh since the mascot is a lion)
Hufflepuff: more passive and submissive mamono, like Kobolds, Kikimoras, Holstaurs, Umi-Onsho, Mandragora, Cockatrice, Mothwomen, Alices, Unicorns etc. Probably also more community based mamono like honeybees, giant ants, hornets, devil bugs etc. I could also slimes and other simple-minded mamono being here.
Ravenclaw: Probably intelligent/inventive Mamono like Hakutaku, Gremlins, Dwarves, Cyclopses as well as magic-oriented mamono like Witches, Dark Mages, Liches, Baphomets, Familiars etc. (possibly also a lot of harpies what with the "raven" theme)
Slytherin: Probably most Lamia, Arachnes and Chaos-Girls (Shoggoths, Mind Flayers etc) Demons, Devils and other "radical faction" mamono, the more regal/domineering and/or sadistic types like Dragons, Pharoahs, Dark Elves, Vampires, Wights, Vamp Mosquitoes, Manticores, Girtablilu, Werebats and possibly alot of Undead mamono as well, what with there association with Dark arts. (also Danuki, obviously)
More outright agressive Mamono like Hellhounds, minotaurs and Ogres I could see in being in either gryffandor or slytherin depending on just how sadistic they are. Amazons too since they have both the "proud warrior" aspect and keeping their males subservient aspect.
Succubi I could see being in any house depending on their personilty, since they are common, and often the result of monsterized humans with different pre-existing personilties. Same with Alps, for the latter reason.