Dr. Carol Heisler was researching a cure for arthritis when she mutated herself to a size-changer who grows to giant heights. The transformations initially left her in a confused state of mind , leading to unwitting rampages. She eventually gained better control of her powers and can grow to greater heights by sheer force of will. She has also transformed into a giant whale like creature in the past. She also has telepathic powers which once sent her into a rampage when she read the mind of a man who killed baby seals.
Since gaining control of her powers Carol has been a supporting member of the Femforce. Although she is not a full time member she helps them whenever possible. She prefers to continue her research rather than be a superhero.
Many times Carol fights to save animals and the environment.
Garganta has the power to grow tall and has been able to go up to around 200ft tall, at one point she was stuck at a height of 50ft tall but now has full control over her powers through practice.