Metal block

Metal blocks (also formatted as Metal Blocks) are large metallic blocks that are found in the Paper Mario series. These blocks typically serve as barriers that block a path to either a new or a hidden area. The only way Mario can destroy the blocks and proceed beyond them is by using the Ultra Hammer, which he finds in Chapter 5 during his expedition into Mt. Lavalava. Luigi will be sitting on one after Mario gets an Ultra Hammer.

In Paper Mario: The Thousand-Year Door, a few metal blocks can be found in two rooms of the Riddle Tower in the Palace of Shadow. Here, they cannot be destroyed, even with the Ultra Hammer; instead, Mario must smash the corresponding stone blocks in the other room to eliminate them.

Paper Mario

 * "Your Hammer can shatter this block. Break it down, Mario!"

Paper Mario: The Thousand-Year Door

 * "You can't break this block. Seriously. No matter what you do, you can't break this."