Very little is known about Mad Harriet's past before she joined the Female Furies. It is presumed she resided in Granny's orphanage, where she was trained in special tactics.
The Battle With Supergirl
During Granny Goodness' mission to destroy Earth, she ran into some conflict with Supergirl and Jimmy Olsen. She summoned the Female Furies to take care of the two, but they had trouble with her. Superman soon arrived, which excited the girls. Mad Harriet and Lashina were knocked away, but with Stompa's help, the Furies defeated Superman and Supergirl. The Furies brought Superman before Darkseid, but Supergirl soon came to his rescue. Mad Harriet immediately attempted to attack Supergirl, but the heroine was able to use her as a shield for Stompa's attacks. After Superman and Supergirl escaped, Darkseid ordered the Furies to punish Granny for her failure.
After Granny Goodness had brainwashed Superman into joining Darkseid's army, Mad Harriet and the other Furies were seen as his teammates. However, Superman soon regained his memory and returned to Apokolips. There, he was ambushed by his former allies, who all tackled him as he was flying. As a last resort, Superman smashed into a fiery pillar, leaving the Furies to fall one after another.
The War on Apokolips
With Darkseid missing, a war broke out on Apokolips. Virman Vundabar and Kanto were on the opposing end, while Mad Harriet was allied with Bernadeth, Granny Goodness, and the other Female Furies. When Darkseid returned, having been unintentionally resurrected by Lex Luthor, Mad Harriet quickly and fearfully bowed to him.
Powers and abilities
Mad Harriet wears retracting claws that extend from her knuckles. She also has the strength and endurance of a normal New God, and cannot feel pain.