Headmasters animated series
Returning to planet Master after being forced off of Earth when his Transtector’s weak spot was exposed, Scorponok took refuge beneath the surface of the planet, where his Transtector detected the presence of G-Metal ore. He planned to forge it into a shield to counter Fortress Maximus’s Master Sword, but was aware that the Master Sword was even more durable than G-Metal alone, and abducted Wheelie in order to trade him for the secrets of the sword's construction.
With this information, Scorponok perfected the Zarak Shield despite repeated attempts by the Autobots to prevent it. During a battle with Fortress Maximus, the shield proved strong enough to hold off an attack by the Master Sword, allowing Scorponok to claim victory in the fight and return to Earth to begin his final plan.