Marie co-hosts "The Space Show," a wildly popular intergalactic variety program, alongside Neppo, sharing his ambitions for ultimate power. She aids Neppo's pursuit of the children to secure Zughan, the rare plant substance vital for activating the Pet Star weapon and achieving godlike status. Physically, Marie resembles a canine alien, a trait shared with Pochi Rickman, though their specific species connection remains undefined.

At a critical interstellar festival climax, Marie directly confronts the children and their allies in battle, notably fighting alongside an evil robot against the young protagonists. This conflict culminates in her defeat as the children succeed in stopping Neppo's plan. The narrative hints at, but never confirms, a possible past relationship or acquaintance between Marie and Pochi. Her role centers solely on her involvement in this central conflict surrounding Neppo's scheme.