MaDall was a female Zygerrian who, during the Age of the Empire, ran a relatively small enslavement empire located on the planet Oon. In 4 BBY, a fresh group of enslaved people, gathered from all over the Lothal sector, was delivered to her, and MaDall picked out one of the new arrivals, a Mandalorian named Sabine Wren, to serve as her personal attendant. However, Wren had intentionally allowed herself to be captured with the goal of freeing all of the Zygerrian's slaves. MaDall engaged the Mandalorian after discovering that Wren had disabled her own shock collar and shown the other slaves how to do the same; however, she was ultimately defeated. MaDall believed that Wren and her friends would execute her as punishment for her wrongdoings, but she was instead granted her freedom. Wren suggested that the Zygerrian, who felt she had no further purpose, should instead use her skills to oppose the Galactic Empire.
MaDall's initial appearance was in "Return of the Slavers," a comic strip featured in the Star Wars Rebels Magazine, specifically in its fifth edition. The character design for MaDall drew inspiration from Miraj Scintel, a queen of the Zygerrian species who was first introduced in "Slaves of the Republic," which is the twelfth episode of Star Wars: The Clone Wars' fourth season.