Saki

Saki is an Elder Devil that appears in Monster Musume: Everyday Life with Monster Girls Online.

Zoological Classification
Elder Devils (エルダーデビル, Erudā Debiru) are devils that have the bodies of humans in their adulthood. Appearing even older than Greater Devils, they are the voluptuous/highest class of Devil, and boasts the largest average wingspan.

Though it's unclear if it's because of their older apparent age, Elder Devils have the longest lifespans of all Devil species, and it's not uncommon for members to live several centuries. It might have to do with the their extremely long lifespans, but Elder Devils are quite calm and composed, and are beyond playing pranks.

Trivia

 * Her name, "Saki", comes from "Succubus".
 * While she can eat pretty much any food, her favorite is a man's life energy.
 * Saki is the second monster girl who was released in advance of her scene Osewa (she gets rubbed oil on her back). Here's the link: