*Heloise is a very short person and has dirty blonde hair pulled into a ponytail and greyish-blue eyes. She has a long stitched scar on her forehead of unknown origin that is usually half-covered by her hair. She usually wears a red robe-like dress that terminates in a curved point. She does not appear to possess legs (or at least not normal ones) as they are always hidden. However, it has been shown on a few occasions that she makes footprints in animal form since she has the ability to shapeshift. In Heads Will Roll, she’s also revealed to be able to detach her head from her body.

Heloise shows that she is intelligent, confident and a bit selfish. She has been known to enjoy her position as the Head of R&D (research and development) at Misery Inc. where she makes products to cause misery.

Even though Heloise seems like she's vicious, crafty, and a bit of prank-master, Heloise has shown to have a good side to her as she can be a very loyal, considerate, kind, romantic, and a good friend. She's very sensitive when someone teases or makes fun of her and will often react with rage especially when people call her a little girl. She also appears to be quite physically strong, despite her size, and relatively fearless.

In season 2, Heloise seems more happy, cheerful, and bubbly, yet she still retains her sadistic ways. She smiles more while in the first season she was sarcastic. Her aunt Pomegranate gave her the cutest nickname in What's Up With Heloise?, Poppy is what her aunt called her.

When someone gets in her way or makes her angry enough, Heloise will often try to destroy them or frighten them away, like in the episode Panda-Monium where she tries to get rid of the pandas by showing them how evil she is.*