Vampires, Elves, Succubus. The Big 3 of "monster girls but not really" used by stories trying to cash in on monster girls. But I can excuse it here given that this is probably heavily inspired by Monster Musume and we'll get more interesting girls overtime.
Honorable mention to Catgirls. Depends a lot on the execution but most stories treat it as "girl with cat ears".
Well let's hmm so he has a girlfriend lamia and now a vampire woman proposed to him (well she is trying) and wants to fuck him hm oh well it's his problem not mine