Texas Mack, a hulking American super robot under US military command, is jointly piloted by siblings Jack and Mary King. Its design blends rugged cowboy motifs with advanced weaponry, including a detachable "Hat Machine" unit controlled by Mary—a multirole aircraft doubling as a shield, scouting scope, or nimble fighter jet. The robot’s weathered exterior sports a brown armored vest, twin gun holsters, a frayed yellow cape, and a crimson headdress adorned with orange feathers exposed when the Hat Machine separates.

Armed with transforming revolvers that shift into blades, maces, or combine into a rifle or shotgun, Texas Mack also wields a semi-automatic rifle and an energy lasso. Its most devastating armament, a colossal cannon, is housed in a coffin-shaped module requiring strategic placement across battlefields due to mobility constraints during deployment. Short-range thrusters enable aerial bursts, while sustained travel depends on Pasture King—a horse-inspired support mech ridden by Jack’s canine companion.

Created by Dr. King, Texas Mack was field-tested against Japan’s Getter Robo to evaluate its efficacy against Mechasaurus threats. It overpowered Getter 1 and Getter 2 in combat but fell to Getter 3, securing an official victory only through a contentious post-battle strike. Later, it single-handedly repelled a Mechasaurus assault but relied on Getter 3’s aid when a second enemy overwhelmed its systems. Post-mission analysis prompted the King siblings to retreat stateside for upgrades, though the robot never reentered subsequent conflicts.

The coffin-carried cannon and its tactical restrictions pay homage to *Django*’s Western grit, reinforcing the machine’s cinematic cowboy essence. Texas Mack’s story arc focuses on battlefield adaptation and incremental refinement, its operational legacy cemented within the confines of its original OVA deployment.