One day, Gwen Stacy was bitten by a radioactive spider. The bite resulted in Gwen receiving powers. The most noticeable one, the ability to grow into a giant with muscles. It took a lot of time to figure out a costume that could stretch with her body as she transformed.

When she did figure out the costume, she grew, flexed and reveled in her new identity as a superhero!

Btw, by giant i mean, she's the size of an building, have fun