Mr. Mosaic was one of the Penguin's head lieutenants. Serving as the link between Oswald and Mayor Hady, Mosaic would be vital in funding Hady's re-election campaign. Mosaic was noted for having a visible disfiguration consisting of several permanent red blots.
Mosaic would be well acquainted with Jill Hampton, being one of her only resources in trying to kill Mr. Combustible, Hypnotic, the Imperceptible Man and Mr. Toxic for money. After Jill would screw up, Mosaic would get Snakeskin to kill her. Continuing to work in the employ of Cobblepot, much like Combustible and Hypnotic, Mosaic would be present when Ignatius Ogilvy would seize control of the operation. Becoming one of Ogilvy's most trusted lieutenants, Mosaic staged a robbery when the latter launched a Man-Bat pandemic on the 900 Block of Gotham City. Mosaic was then captured by the Batman and tortured for information, though the vigilante ended up letting the criminal go in favour of Ogilvy. Mosaic was then incarcerated in Blackgate Penitentiary, this led to him joining Bane against Scarecrow in the Arkham War. Eventually he was asked by the Penguin to gather his men for war against Falcone's Mob.