It was developed to wage war, but due to a malfunction that made it peaceful, the scientists released it. It can't lift its mechanical arm, but it can drag it easily and use it to defend itself.
A prototype for a war machine, but its programming malfunctioned, making it peaceful. Its mechanical arm is too heavy for it to lift.
Due to preferring not to fight, its creators released it into the wild. The thick metal of its arm makes it a handy shield.