Although covered with layers of clothing, Mortimer has a slender appearance with fair skin, short pink twintails with a choppy fringe, pitch black eyes, long lashes, and a tall stature. Despite having a slender physique, she does possess some muscle and strength. Her scythe is completely black, almost shadow like, with a sharp edge and jagged snath.

• Mortimer wears a maroon cardigan accompanied by a black button-down with a white collar. Pink hearts are sewn into the collar.
• She wears a high waisted skirt, hiding her waist and a bit of her thighs.
• Her thigh-high socks are sheer, almost the same color of her cardigan.
• Morty wears pitch black gloves, hiding her thin slender hands.
• Her shoes are flat Mary Janes, they don't add much height to her.

Not much is know about Mortimer, she grew up quite reclusive and didn't allow anyone to get close to her nor her family. Whenever her loved ones were questioned about Mortimer, they knew to speak in varied amounts. Morty didn't want friendships or relationships in general, she wanted to be left alone. And that's how she stayed for many years.

Though, one day in the midst of night, she was kidnapped by a crow-like demon. The demon sought after her soul to eat, and the only way to retrieve it, was to kill her. Thus, the demon did. Morty was then forcefully drowned. On the brink of death, she offered a pact with the demon. In exchange for her life, she'd slay not just monsters, but humans as well for souls. The gluttonous demon reluctantly agreed, thus Mortimer's life was spared. From that day forward, she became prisoner to her new owner. Living everyday as if she were already dead, assassinating others for their souls.

Mortimer was found by the Rescue Team, and they offered help to free her from her owner and sins. At first she fought it, she knew what'll come to be if she was found trying to escape. Eventually, she realized how desperately she wanted to escape. She decided to riot, with the help of the Rescue Team. Once she was freed, it was up to her to become her own person. To live once again, trying to recrudesce. Mortimer vowed to become stronger, and protect the ones she holds dear to her. Her past will not define her.

Mortimer isn't who she says she is, because everything is truly a lie. For the most part at least. Her real name is ░░░░░░. ░░░░░░ faked her own death a long time ago to protect her family. She knew what the future held for her, and decided to change it. She made the tough decision to live on as an entirely new person. Leaving her family and friends behind. Although she lied about her past, her kidnapping and ownership remains the truth. ░░░░░░ has yet to reveal this information to anyone, and she longs to see her family again. Knowing she can't, it's an emotional burden she carries on her own.

• Unlike others, Mortimer has no known quirk. She relies solely on her own strength, wits, and agility.
• Mortimer has suffered from a lot of emotional trauma, but she copes and battles it. She will not let her mental health be the downfall of her or anyone she loves. She's often seen as the Wise Mom Friend™
• It's unknown why Morty refuses to take off her gloves, but if she must she will.
• Morty comes off as mysterious and scary, but in reality she's lost in thought. She's quite the thinker.
• In order to feel better about herself, she trains not only her body, but her mind as well. She feels in control and ready to face anything afterwards.

• Riddles and puzzles, she loves to think about all possible outcomes and analyze what she's given.
• Cats, Morty isn't one to show affection very well, but around cats she just can't help it!
• Games, Morty is very competitive and will not stop until she's won.
• Reading and books, she loves to read old literature and take in everything.
• A nice bath can always soothe Morty's thoughts and worries, she even has her own rubber duckie!

• Wasting her time and energy on socializing. If she doesn't have to speak to you, she won't. Although she won't be rude if spoken to.
• People worrying about her, she understands where they're coming from but she's more than capable of handling herself. If anything it makes her feel as you underestimate her.
• Being called Morty if you're not an ally.
• Children, not that she hates them or finds them annoying! She just can't seem to appeal to them, they don't like her!
• Fusing with others, she hates feeling trapped with another person and prefers NOT to fuse. Only exception is her lover, Cecil.