I'll think about elves. There's no shortage of elf pics though, so it won't be high priority.
Medusa preview - Profile1 pic:

Monster Girl Pack of mythological proportions progress:
Completed:
Satyr (100% Nymphomaniac rate!)
Werewolf/Wolfgirl
Tengu
Harpy (Highly aggressive! Can start with PCHate as high as 50!)
Yeti (I found a grand total of two H-pics worth mentioning. Only one was good enough to go in. I had to go to deviantart to find a decent profile pic.)
Medusa (Unique. The most antagonistic girl to go in the game yet. Adventurer, Aggressive, Assassin, Merciless, Fearless, Malformed, Tsundere, Yandere, Iron Will, Sadistic, Strong, Tough, Basic Magic, Strong Magic, PCHate 100, 0 Happiness, 25 base Combat & Magic, 0 Obedience, etc. I've half a mind to write some custom interaction scripts for her where one wrong move gets the player turned to stone and results in game over.)
Working on/Planned:
Angel
Succubus
Mermaid
Vampire
Naga/Lamia
Kappa
Phoenix
Unicorn
Oni/Ogre
Elves (Maybe? Depends on how fast I finish the rest)
Okami Amaterasu (Unique)
Given Up (Can't find pics. I appear to have disproved Rule 34.....):
Thunderbird (I don't mean the personification of Mozilla Thunderbird either!)
Quetzalcoatl (Unique)
Still taking (mythological) suggestions!