Game they appeared in first:
Unpredictable moves, ability to create weapony from her imagination. (Mostly involving toys, bombs, guns and odd weapons example. Banjo, Footballs)
Original or Canon
Once a war orphan slave named Patricia, Peacock’s body was gruesomely mutilated by slave traders that captured her. She was rescued by Dr. Avian’s Anti-Skullgirls Labs, and rebuilt with a reality-defying arsenal of biomechanical weaponry: the Argus System augmented her body, and the Avery Unit gave her access to unprecedented weaponry.
Alas, they couldn’t do anything for her mind: Peacock’s damaged psyche and abiding love of cartoons shaped her new “toys” into a terrifying gang of cronies, who she has no qualms using to paint the town red… with blood. Terrifying as she is, she may be the kingdom’s best bet against the Skullgirl.
: Canon http://skullgirls.wikia.com/wiki/Peacock