Mario franchise strategy guide/Items/Metal Box
A Metal Box is an green cube in the Super Mario Bros. series that has appeared in several video games. It makes its first appearance in Super Mario 64 and contains the Metal Cap, which can turn Mario into metal. This has the effect of making him heavier than normal, allowing him to perform actions such as walking on the sea floor, and withstanding wind gusts. It appears again in Super Smash Bros. Melee as an item able to turn characters into metal, except that there is no Metal Cap because the box itself activates the transformation.