Origin

Melodia became infatuated with High Evolutionary early in her career and kept trying to impress him with her work. This infatuation continued through her marriage to Jeremy Stillwell and the birth of her three children, Harlan, Farley and Shannon Stillwell.

After she changed her name to Madame Monstrosity she would punish any who she though was stealing her work, this included killing Harlan and Farley for creating Fly and Scorpion, respectfully. She even threatened Shannon when she thought she created Spider-Boy, even though he was one of Madame own creations that she forgot about.

At some point Madame Monstrosity combine her husband Jeremy's DNA with a owl but when she split them back up the owl got Jeremy's intelligence and the human became owl like.

Later, Madame Monstrosity met with the High Evolutionary, but the geneticist was unimpressed with Madame's work, and this broke the woman, causing her to lose her mind more and she became obsessed with Spider-Boy, the experiment that got away.

Creation

Madame Monstrosity was created by Dan Slott and Paco Medina and first appeared in the story, The Mother of Invention. She would later become the main villain in the first two story arcs of Spider-Boy.

Major Story Arcs

Full Circle

Madame Monstrosity is approached by Mister Negative with a deal. He has kidnapped a bunch of people from FEAST, a homeless shelter he controls, and if she turned the men into Humanimals that he could control, she could have the women and children to use for her experiments.

Madame, of course agreed. This is how she got Bailey and Tabitha Briggs, along with Eli.

Webless Wonder

Madame Monstrosity learns that Spider-Boy is one of her experiments that she has forgotten about. She then spends her resources to capture him and learn how he made her forget her experiment.

To this end she sent Hellifino to capture Spider-Boy but he failed only getting the experiment number tattooed on Spider-Boy's neck. This lead her to create Boy-Spider, a reverse copy of Spider-Boy. This gave her the information she would need to capture the boy web-slinger.

Fun and Games

Madame Monstrosity captured Spider-Boy and now she used his connection to Christina Xu to learn how he made her forget him.

She planned to destroy Spider-Boy but before she could Spider-Man, Captain America, The Toy Soldier, Thor and Squirrel Girl come to Stillwell Farm to rescue their friend. Madame unleashes her Humanimals on the heroes, but once the Humanimals learn that Madame could change them back they rebel and join the heroes.

This leads Madame to take drastic measure and combine all the animal DNA and inject herself becoming a monstrosity. The Heroes and Humanimals look to be defeated but monster Madame Monstrosity is teleported away.

It seems the High Evolutionary, has finally noticed Madame work, but doesn't want to work with her, he want to experiment on her.