Role in the short film
In the cartoon, Mr. Incredible and Frozone found out the radioactive rivet they discovered is linked to a villain no other than Lady Lightbug. It is shown that she stole the city bridge and took it to her hideout at an old abandoned carnival. At the carnival, Lightbug emerges from an abandoned funhouse where she attacks the heroes, much to their shock. Planning to take over the city, Lightbug then traps Frozone with her silk power to which Mr. Incredible tries to stop her with the abandoned Ferris wheel he picked up but she ultimately dodges it. Riding on a rollercoaster, Mr. Incredible tackles her as she ends up trapped in a jar placed on the West River Bridge. Lightbug is last seen defeated as a plan to take revenge against superheroes.
In the optional commentary recorded by the real Frozone and Mr. Incredible, it was noted that Lady Lightbug was a villain made up for the cartoon and does not really exist in The Incredibles. She was also depicted as a communist for propaganda purposes.