Moonbay is a free-spirited transporter who operates the Gustav, a large armored insect-type Zoid capable of hauling heavy cargo. She first appears when she encounters Van and Fiona in the desert after the Shield Liger has been damaged, and she offers her mechanical expertise to help repair it. Though she initially presents herself as a simple courier, it later becomes clear that she often smuggles weapons and takes jobs from whichever side pays the most, whether the Helic Republic or the Guylos Empire. Despite this mercenary streak, she is fundamentally kind, honorable, and loyal to those she travels with. She has a strong independent streak and is not afraid to speak her mind, but she is also quick to help others when they are in genuine trouble.

Moonbay comes from a very large family, which taught her how to be social and resourceful from a young age. She inherited a natural gift for sensing the flow of energies within Zoids, making her an exceptionally skilled mechanic. This ability allows her to identify weak points and pressure points in Zoids, and she also knows traditional moxibustion techniques that can accelerate a Zoid’s recovery. Beyond mechanical work, she is a capable cook and manages money wisely, often acting as the group’s practical anchor when it comes to finances.

Her role in the story is that of a support member who keeps the team’s Zoids operational and provides transportation. She is a main character throughout both the original Zoids: Chaotic Century and its sequel Zoids: Guardian Force. A key relationship is with Irvine, a mercenary who joins the group around the same time. The two have known each other for a while and constantly bicker, but there is an unspoken romantic tension between them; Moonbay has feelings for Irvine but refuses to admit it. She also develops a strong friendship with Van and Fiona, acting as an older-sister figure who looks out for them while still maintaining her own independent agenda.

Over the course of the series, Moonbay’s motivations remain tied to survival and profit, but she gradually becomes more invested in the group’s larger mission. She shows considerable personal growth in learning to prioritize her companions over pure financial gain, though she never loses her pragmatic, street-smart edge. Her engineering and repair skills prove invaluable during many battles, and she occasionally pilots other Zoids, such as a Pteras, when the situation demands it. Her combination of mechanical talent, resourcefulness, and fierce loyalty makes her an indispensable part of the team.