Mario franchise strategy guide/Items/Metal Cap

The Metal Cap is the metallic cap that Mario could pick up in Super Mario 64. If Mario smashed a green !-block, the cap would come out, and Mario would catch it. In Super Mario 64 DS, Wario is the only character who can become metal. When metal, Mario (or Wario) does not need to breathe, allowing him to walk through poisonous gases and lava and stay under water until the cap wear's off. You can walk on ocean floors, which can be both an advantage and a disadvantage. Also, you cannot be blown away by strong gusts of wind. Enemies are more easily killed (i.e. you just touch them), and you cannot be shocked.

The green !-block is also seen in Super Smash Bros. Melee, and makes your character heavier after directly attacking or picking up the item (projectiles will destroy it). This power up is good in that you are less likely to be knocked from the stage but bad in that you cannot stay airborne for as long and fall quicker when knocked off the platform. It also makes the character mute, good for those with distinctive sounds while charging attacks.