Dr. Carol Heisler volunteered to test her own scientific formula, an outgrowth of the formula Joan Wayne developed. The variation in the formula, combined with her body chemistry, caused her to become filled with energy and her body to grow to gigantic proportions. Her altered state caused her to go on a rampage as she could not control the energy coursing through her. The Femforce was able to stop her and return her to her normal size but shortly thereafter the government decided to further experiment with her and determine her capabilities. Reactivating her growth powers with electricity, they found she could not be controlled and she was off on another rampage. It seemed she's met her end in the depths of the Atlantic but instead she mutated into a giant sea mammal.

The marauding space Gammazons plucked her from her peaceful life in the deep blue sea to help them in their efforts to subdue the planet, but the Femforce once again came toher rescue. With practice, she's learned to control her size-changing abilities and has developed the empathic powers that previously caused her to be overwhelmed with emotion and to go on rampages.

Garganta can control her size, growing from 5'6" to a maximum of 60'6" through willpower. She also has empathic powers which enable her to sense and influence emotions in others.

When she's not lounging about Femforce Headquarters where she's always a welcome guest, Garganta has launched a showbiz career, under the management of the less than trustworthy Stella Stargaze, taking advantage of her size-changing abilities as a unique talent in the entertainment industry.