A Metal Bug's body is nearly identical to a Metal Bug Blox; it is a metallic, silver cube with patterns resembling computer circuitry covering it. A single, glowing yellow eye is present near the center of the front of its body. Four spider-like legs sprout from its sides. These legs are colored white near the core and between the first and second hinges, black around the first hinge and at the tips of the legs, and gray around the second hinge.
A Metal Bug can turn into a Metal Blox for a short time, although it still shows the single yellow eye. When in this form, it cannot be hit or dealt damage.
Metal Bugs are fairly easy to beat, though once it hardens into a Metal Blox it is invulnerable. So just wait until it reverts back to its normal form and continue using physical and magic attacks.