The Bomb Guardian is encountered in Agon Wastes and guards the Morph Ball Bomb upgrade. This boss is a large, armored creature that primarily attacks by rolling around the arena and attempting to crush Samus. It also has a projectile attack. The arena features several half-pipes.
Strategy: The Bomb Guardian is initially invulnerable. Its weakness is revealed when it rolls into a ball. You need to use your Morph Ball and Boost Ball ability in the half-pipes to gain momentum and hit the Bomb Guardian when it's vulnerable. When it's stunned, quickly deploy a Morph Ball Bomb near its exposed underside. Repeat this process. After taking enough damage, it will become more aggressive. Continue to use the Boost Ball and Morph Ball Bombs. Reward: Morph Ball Bomb.