The Metal Cap is an item that first appears in Super Mario 64. It is activated when Mario presses the Green Switch in the Cavern of the Metal Cap in Super Mario 64. It is usually found in a green box. When worn, the player is invulnerable (except for taking damage from falls) and can walk underwater. They may also walk on lava without danger, though will be slowed severely and have a reduced jump. Additionally, it will damage enemies on contact in a similar way to a punch. In Super Mario 64 DS, Wario gets the same powers the Metal Cap grants when he picks up a Power Flower.
The Metal Cap also appears in the Super Smash Bros. series, specifically Melee, Brawl, and Super Smash Bros. for WiiU and 3DS.
In Super Mario Odyssey the metal cap appears as a suit in the coin shops, but it is only appearance, you don't get the skills of Super Mario 64
|Power-ups in the Super Mario Bros. series|