Mephisto from Monster Girl Quest
Recommended tags:
MMephisto, blonde hair, long hair, low-tied long hair, orange eyes, pointy ears, colored skin, scales, lamia, eyes on tail, single earring, robe, black_shirt, necklace, pentagram necklace, witch hat, wide sleeves, outdoors, (If the bangs are showing when she has her hat, just add "parted bangs")
Additional tags:
forked tongue, long tongue,