Personal Info:
Real Name: Sasha
Also Known As: No known Alias
Place Of Birth: Unknown
First Appearance: Batman and Robin Vol.1 #1 (2009) Modern Age Villain
Known Associates: The Red Hood
Group Affiliation: None
Base Of Operations: Gotham City
Grudges: Batman and Robin
Creators: Grant Morrison and Frank Quitely
Gallery: Click
Having been being taught by the Red Hood, Scarlet is highly adept at hand to hand combat, especially with her weapon of choice, a retractable blade.
Sasha came to the United States, and specifically Gotham City, with her father Niko. Niko was a petty criminal who came to Gotham City because his brother Lev had made promises of opportunity. Sasha chose to come along because she always sided with her father against her mother. Her mother believed Niko to be a "no-good shiftless waster." Sasha would later come to believe her mother was perhaps right about Niko all along. But he was still her father.
After her father and Uncle Lev had a job foiled by the new Batman and Robin, they both returned home to Sasha ready to pack up and leave town. It was Batman they were afraid of, but their fears were misplaced. For their failure, Professor Pyg came, killed Uncle Lev and abducted Sasha and her father. They were taken to his hideout, a run down circus ground, where Pyg conducted his experiments on them. Sasha had to watch as Pyg turned her father into a "Dollotron" by grafting a freakish mask to his face and surgically altering him. The drugs and trauma reduced him to another one of Pyg's mindless and obedient servants. Then, the process began on her. It only progressed as far as grafting the mask to her face, mutilating her. Robin had found his way to Pyg's hiding place and gotten himself captured. Pyg stopped working on her so that he could focus on Robin, but Robin broke free of his restraints. During the distraction, Sasha attacked Pyg in a rage and lit him and the whole place on fire. Robin promised to save her, but he became too distracted with pursuing Pyg. She begged for him not to leave her behind, and he tried to reach back for her but tumbled outside with Pyg.
She managed to escape burning along with everything else. However, the entire ordeal had traumatized her. She looked like one of Pyg's Dollotrons now, as did her father. She found where he had been taken in the hospital, slipped into his room during the night, and smothered him to death with a pillow. This was when the Red Hood found her and promised her a way she could channel all that rage.
This was how Sasha became Scarlet, the Red Hood's sidekick. She joined him on his viral marketing campaign of killing criminals and trying to supplant Batman and Robin's place in Gotham City.
Scarlet at DC Database
Scarlet at Batman Wiki
Scarlet at Comic Vine