Little is known about Scallop's origin save that she was once robbed someone at gun point, Batman hit her with his gauntlet spikes in the neck and through her ear. After that Scallop seemed to grow and obsession with piercings and revenge on Batman. She seems to have added more Batman type spikes through her arms and neck and has many more face piercing after her run in with the Batman.
Scallop was created by Peter J. Tomasi, Patrick Gleason and Mick Gray for their run on Batman and Robin.
Major Story Arcs
Batman and Robin Terminus
Scallop has been enlisted into Terminus's army of revenge along with Smush, Bootface , Bat Head and several others that blame the Batman for there current conditions. After the initial meeting, where its revealed that each member had been working for Terminus for some time but never knew it, the army is sent out to spread fear. Their mission is to brand as many people withe the Batman's logo before the sun comes up. Scallop is enjoying sharing her pain with the people of Gotham, until the Bat Family shows up she is knocked out by Dick Grayson. It is assumed that after Terminus's army's defeat Scallop and the others are taken to jail.
Along with Bootface and Bat Head, Scallop was charged by the Secret Society to round up and execute dozens of lawyers and other "powerful Gothamites" at the Gotham City Courthouse and hang their bodies by the East River for all the world to see. Scallop gleefully carries out her task, slaughtering many innocent people before she is thwarted and captured by Two-Face in his war on crime. She eventually escapes his clutches, the only known survivor of Two-Face's perverse sense of "justice."