Metal Guardian looks like a giant metal ball at first, but it reveals an eye when it opens up. Metal Guardian's armored exterior is a highly reflective copper and its core appears to be made of steel or iron. Its design may be vaguely based on Laser Ball considering they both give the same Copy Ability, but its core resembles that of a Wheelie.
Metal Guardian remains secluded and encased in its armor until Kirby approaches it. When encountered, the machine floats in a figure eight and shoot lasers at Kirby. It can shoot a charged laser or three regular lasers in three directions.