I know it's not a furry... But guess what? I MADE MY OWN ADVENTURE TIME CHARACTER! I have been waiting to make my own and I finally had the time to do so... Sooooo without further ado...:

Here is Annatheley... Of Anna for short.
She is from the Nightosphere, where Marceline is from. In my head cannon, she is Marcie's personal assistant... Or more like her personal assassin.
I don't know what it is.. but I have a deep passion for Shadow Manipulation. Sooo.. Anna here, being an assassin, fights and uses the shadows to her own advantages. :)

Her details are there, but here they are as well:

Name: Annathelay (Nickname: Anna)
Age: ??? (She is a demoness and was practically around since Marcie was born.. so even older than Marcie.)
Sign: Unknown due to unknown age
Home: Nightosphere; but travels around with Marcie.
Likes: Shadow Play, weapons, protecting Marcie at all costs, the color black (And grey and red too), Nighttime, and winning battles.
Dislikes: Dogs, Loud beings, the purple flub princess... What was her name again? Oh.. LSP... Daytime, and losing battles.
Favorite food: Pizza and energy from a youthful spirit.
Abilities/Magical Properties: Shadow Manipulation/Assassin Training

Personal details:
Hair: Little past shoulder, straight, black hair with one piece that is red
Eyes: Red cat slits
Body: Slim like Marcies, with grey demon tail (with attached black fur at the spade) and gray demon horns (again with attached black fur at the tips)
Clothing: Grey strapless sweetheart top with black lace on the chest. Black pants with rips in the legs. Black belt with grey studs, and black boots. Also wears a black choker around her neck and two black wristbands/bracelets.

**I DO NOT OWN ADVENTURE TIME! This is just a character I wanted to create for my own head cannon space. :) **