A scientist at the Goodie Gum factory searching for the perfect flavor. She identifies the alien contamination in the gum and collaborates with Daffy and Porky to develop a counter-agent using rotten egg extract. Captured by the Invader, she is later rescued and helps save Earth from the asteroid. She ultimately discovers that the asteroid's crystals are the missing ingredient for her gum recipe and shares a romantic moment with Porky.
Their employment develops into a joint scientific mission.
Petunia offers Porky and Daffy jobs at the Goodie Gum factory, and the three later develop a plan using her rotten egg extract.
Petunia becomes a direct victim of the Invader's operation.
The Invader captures Petunia after the countermeasure operation begins.