The Spring Metal is an Emblem Heartless that is found in Kingdom Hearts II Final Mix.
A Spring Metal has a smooth, conical body that is predominantly cyan with a white swirling pattern at its base and a Heartless emblem emblazoned on its chest. The top of its body flares outward and forms a jagged "collar" below the Heartless's spherical, pitch black head. It also wears a conical, blue white hat that has a cyan-colored, jagged brim and a thin, curled tip. Like many Heartless, the Spring Metal has glowing yellow eyes. Its seemingly useless feet sport three small, thin toes.
At first glance, the Spring Metal's name does not seem to match the usual naming scheme for its family of Heartless. While it does reference a musical term, "metal" (referring to heavy metal), it does not seem to include a color. "Spring" could refer to the color spring green, though no part of the Heartless is green. However, there are several shades of spring green that are closer to cyan, which is present on the Heartless.
Like the Emerald Blues, the Spring Metal uses wind-based attacks which are, as you might have guessed, at a much faster rate than the Emerald Blues.
It starts off by creating a small tornado around it, and immediately proceeds to create a huge tornado that sends Sora flying. The breaks it takes in between these two attacks are rather short, so attack and heal when you must.