Buzz Cunningham, a second-generation Earth citizen, works as a courier with Leo Conrad. His job initially provides a neutral position in the Republic-Empire conflict, letting him leverage negotiation skills and connections to bypass military checkpoints. This neutrality becomes harder to maintain once he joins Sally Land's mission.

Before the series, Buzz and Leo partnered as salvage collectors and couriers. During this period, Buzz cultivated connections within the Empire, easing movement across territories. His practical, money-focused approach occasionally clashes with Leo's idealism, but their strong partnership endures. Buzz acts as an older brother figure to Leo, offering grounded perspective.

Unlike most, Buzz doesn't pilot a Zoid. He drives a self-repaired, jeep-like vehicle from the 21st century. This vehicle proves essential for transporting Sally and handling group logistics, demonstrating remarkable durability by hauling heavy loads, including Zoids like Raptoria and multiple Jaminga. Buzz briefly owns a transport ship early on, lost escaping Imperial territory. The Republican Army later supplies the group with a replacement ship.

His key relationships include a trusted partnership with Leo, whom he consistently supports. He frequently transports Sally, forging a close friendship. Buzz contributes strategically to missions, such as orchestrating a Jaminga diversion to rescue Leo's Zoid from an Imperial base. A recurring pattern involves Buzz temporarily gaining valuable treasures or wealth, only to lose them unexpectedly.

As the overarching conflict escalates, Buzz evolves from neutral courier to active participant in Sally's quest to find her grandfather and activate terraforming Regeneration Cubes. He provides vital transportation and logistical support for the group throughout this mission.