Alright this is similar to a question that I wrote in another discussion but instead of a particular character what type of monsters would you choose for a mate. For me it would be the following in no particular order.
1. Naga
2. Mermaid
3. Harpy
4. Centaur
5. Nixie
6. Kitsune
7. Elf
8. Ant Girl
9. Alurane
10. Arachne
11. Dragon
12. Jinx
13. Giant Butterfly
14. Cyclops
15. Slime