Here's an idea- Make the creature a moon rabbit. Really the same thing, just looks a bit different.
http://en.wikipedia.org/wiki/Moon_rabbit

Ooh! Okay, edited the post. I also edited her history and some other things.
I hope the edit is good.

It's great :D

Name: Serene
Gender: Female
Species: Hippocampus
Student or Staff: Student: Equine Class
Preferred weapon: Ninja Stars
History: Her Hippocampus parents died from an unknown disease when she was 7. She was found on the shore by humans, and they quickly took her in for experiments. They raised her as if she was their own, but when she found out they took her in for experiments only, she got mad and started hating humans. She then ran away and managed to take care of herself in the wild. When she turned 12, she learned how to use her powers to morph herself with a human appearance. She found the school when she was exploring the area.
Age: 16
Personality: Fierce, strong, loyal, sneaky, can be loud but normally quiet while training.
Human form (N/A for Humaniod class):
Monster form:
Other: Likes a boy, but doesn't like to admit it.

Accepted!
Also, to everyone, we need people to play teachers.

Name: Astrid
Gender: female
Species: kitsune
Student or Staff:
Preferred weapon: scythe
History: Her parents died, leaving her in the care of her little sister who disappeared later. She blames herself for her sister's disappearance
Age: 17 (I know the kitsune legend about the age and tails, but is it okay if I change the life span?)
Personality: kind, stubborn, somewhat mischievous
Human form (N/A for Humaniod class):
Just imagine hair and fur the color of her monster form's fur
Monster form:
Other: She can't hide her tail when she's in human form, but she can hide her ears. fruit salad

Name: Yukino Usagi
Gender:Female
Species:Kitsune
Student or Staff: Student
Preferred weapon: She prefers a sword but would take a knife or use her foxfire if need be
History: She has just let bed with her family until she heard of this school and joined
Age:16
Personality: Very silly and happy-go- lucky
Human form (N/A for Humaniod class):

Monster form:
Other: Fruit salad XD

Accepted!!!!
Wow, Kitsunes are popular!

Thanks Kitsume :3 Yeah, aha I really like kitsunes 'cuz they're like foxes lol

@Snocone2,
Cute character! Yesh, they seem so popular since they are like foxes. A kitsune was one of my choices, but I was like nah.
@Kitsumetails,
At about how many characters more until we start?