Penny is a ghost who dresses in stereotypical Southern Belle garb complete with a dress and yellow bonnet. She also has pale blue skin and buck teeth. She speaks with a Southern accent.
Penny Plasm was very lonely until she encountered the Warriors. She can be very flirtatious and instantly attempts to make any male that comes to her domain her husband. She can be prone to jealousy, such as trying to keep Vambre away from Prohyas, and can be destructive, as she was willing to kill Prohyas in order to be with him.
In her debut episode, the Warriors arrive at her house and she invites them over. She explained that ever since an event involving power tools and a monkey claw and a doily, she was lonely in her house. Vambre is grossed out by the phantom's constant kissing and she invites Prohyas for a tour of the house. She also kicked Vambre out so she and Prohyas can have some privacy and set up a mystical force field to prevent her from getting in. Penny gave Prohyas some tea and cookies and massages and decided that in order for them to be together, he should die and become a ghost. After being ejected with Seeds of the Undead thanks to Vambre and Prohyas, which is her weakness, she temporarely loses her powers. She apologizes to Prohyas for her behavior and lones for another suitor. When Phil comes, she immediately took him in and kissed him, much to Phil's delight.
- Flight: As a ghost, Penny has the ability to fly.
- Intangibility: Solid objects or people (such as Prohyas) can safely pass through her.
- Energy Manipulation: She can create energy hands that can open, close, and attack others.
- Object Generation: She can manifest inanimate objects, which he can send flying at her opponents.
- Force Field Projection: She can generate force fields to protect her home.