Metal Box

The Metal Box is a green ! Block appearing in Super Mario 64. By breaking it, Mario was able to get the Metal Cap. The switch to turn on the Metal Boxes is located in the Metal Cavern, a secret area inside Hazy Maze Cave.

The Metal Box also appeared as an item in Super Smash Bros. Melee, and returns again in the sequel, Super Smash Bros. Brawl. When used, the character became Metal for a short period of time, but also becomes much heavier, which meant it was harder to KO them by blasting them away, although the player would fall much faster, making it hard to get back on the stage. Additionally, a trophy of the Metal Box appeared.

Trophy Information from Super Smash Bros. Melee
''First spotted in Super Mario 64, the Metal Box holds the power to turn your character briefly into heavy metal. Your mass is exponentially greater while metallic, making it difficult for others to throw you. Be careful though: not only will you move a bit slower, but you'll also fall much more quickly than you ordinarily would.''

Trophy Information from Super Smash Bros. Brawl
''A green box that transforms whoever attacks it into metal. In metal form, you're a lot heavier than normal, so middling and even strong attacks don't move you too much, and standard attacks won't even make you flinch. The time you spend in metal form decreases with the damage you take. In Super Mario 64, the weight of the metal form allowed you to walk underwater.''