Barbara Gordon is the Gotham City vigilante known as Batgirl.
Barbara took part in the first adventure that drew Maxwell in her world.
Later, when the Anti-Monitor was putting in motion a scheme to consume her universe by manipulating the villain element, Barbara along with the whole Batman Family were lured into a trap by Joker, Harley Quinn, Bane, Clayface, Firefly and Catwoman. They were about to get killed off when Maxwell and his sister Lily turned up, brough back into their universe by the Phantom Stranger. Maxwell and Lily help the Batman Family to get the upper hand and beat the villains.
Later, when the cosmic Crisis was deteriorating, Batgirl -along with every available hero- was summoned to the Fortress of Solitude by the Justice League. During the gathering, Barbara and her friend Kara got a brief scuffle after which they made up. Batgirl and all Earth heroes were tasked with keeping watch over the planet while the League took the battle to the Anti-Monitor himself.
This version of the character is exclusive to the continuity of the Scribblenauts Unmasked: A DC Comics Adventure video game series and is an adaptation of Barbara Gordon/Batgirl. The original character was created by Julius Schwartz, Gardner Fox, and Carmine Infantino and first appeared in Detective Comics #359.