Melona is one of the four servants of The Swamp Witch and her strongest minion. Nicknamed "The Protean Assassin" due to her nearly unlimited ability to change form at will, she is skilled in obtaining information and assassination. It is assumed that she was ordered to bring about chaos to the Queen's Blade tournament.

Able to appear in any form, the most common form she appears in is very well endowed woman with pink goo hair that forms bunny ears and has living hands which she can control like any other limb that she uses to cover her otherwise exposed breasts. In this form she is very scantily-clad, wearing a small pink transparent jacket that only covers her shoulders featuring eye-like pauldrons and a collar bound by a heart-shaped emblem with wings and a pink nightie. She wears an equally revealing blouse of the same color and density and wears a pair of pink shoes with a pair of eyes.

In Queen's Blade: Rebellion Melona redesigns her existing wardrobe with her jacket sleeves becoming elbow length and frilly and her skirt becoming floor length. She also changes to open toed shoes and her goo hands hold her breasts differently.

Seductive and alluring, she revels in humiliating her opponents and will not hesitate to kill them if given the opportunity. Despite her malevolent nature she hates being called a monster and becomes very upset, to the point of strangling someone to death for instance. Despite this, she can be reasoned with and is willing to work with her enemies as long as it benefits her and furthers her own goals.

In Queen's Blade: Rebellion her knowledge and judgment increased by having absorbed a certain ancient demon.

She is a shapeshifter not limited by shape or texture who can change the shape of her body freely and instantly. Her mimicry is so proficient that she can even imitate the techniques of the person she has assumed the form of, though her technique mimicry is not perfect and the real technique from the original one it was copied from is generally superior. She can become solid or soft at will and is invulnerable to physical attacks.

She also possesses an ability where she fires her own breast milk at an opponent using the goo arms from her hair to squeeze her breasts. The goo acts as a very efficient corrosive agent that burns through any non-organic matter such as armor, clothing, or even buildings and weapons. She often uses this to humiliate her opponents. Melona's breast milk can also be blocked before it is fired causing her to implode with explosive results.