Isis was the owner of the Vanderchill Ice Factory, which obviously produced ice. Being obsessed with her beauty, she decided to get surgery to freeze her face in order to prevent the effects of aging, but the surgery failed, freezing her blood instead. While this incident gave her ice-based powers, she suffered from inescapable cold as a side effect.
Isis started residing in an underground cave near the planet's magma to warm herself, but that wasn't enough, so she employed a gang of fireflies to melt all the gold of St. Canard, which she would then use to coat the entire city in order to reflect the sunlight and heat up the entire city, thus giving her the warmth she so longingly desired. Darkwing found her cave while giving chase to the fireflies, but she fell in love with him, and decided to take him out on a date. Launchpad eventually found out her plan, forcing her to lock up the two while she proceeded with the plan. Darkwing defeated her by turning her ice machine against her, freezing her solid. The police made a snowman out of her, just for the fun of it, and then took her off to the cooler.
In "Orange is the New Purple", it is revealed that the still-frozen Isis was now kept in an especially cold cell in St. Canard's Maximum Security Penitentiary for the Criminally Crafty. During Negaduck's lockdown of the place, Isis was defrosted by the Fast-Heating Ouchie Strips that Darkwing used in his battle with Camille Chameleon. She came after Darkwing again, but he was able to get away from her by tricking her into kissing a metal pole that he'd placed his hat and cape on while she wasn't looking.