Thugasaurus

Considerably attractive innocent bystander female Janie (13ish) weighing under 100lbs and can barely do a push-up, walks into alone into a dark, deserted alleyway into the bad part of town at midnight completely defenseless and unarmed save for a giant wad of 100 dollar bills.
A thug hopped out of the shadows and cornered Janie.
A mixture of utter surprise and fear cursed Janie. A mugger! How unexpected, Janie did not see this coming. "Eeeek," she cried. "Will someone save me from this shocking and out-of-the-blue turn of events?"
Another thug hopped out of the shadows, bigger and stronger than the previous.
"Well this does not improve my situation at all," Janie complained.
Yet another thug hopped out of the shadows. Too many thugs in one area! The thugs began to fight each other over who will mug Janie.
One last thug hopped out of the shadows. He transformed into a tyrannosaurus four-legged dinosaur thing brontosaurus, and ate the other thugs.
"Huzzah! The process of evolution has saved me! Thank you survival of the fittest!" Janie exclaimed. She hopped onto the dinosaur, shouting "Come Thugasarus! We will rule this town!"
Janie and Thugasaurus, now best friends for life <3 ran into town destroying everything.