? Block

? Blocks, pronounced as Question Blocks, are floating storage containers used throughout the many dimensions. The process behind its creation is a mystery to the public, leading groups like the Woohoo Hooniversity scientists to figure out the meaning behind its technology.

Description
The general description of a ? Block is its yellow cubic shape with a pronounced "?" icon on the horizontal sides. Some ? Blocks have small holes cut out on the corners of each side, while ? Blocks like those on Dinosaur Land leave out holes in favor of its smooth appearance.

The variant of ? Blocks used in the Mushroom Kingdom are made out of a secret metallic material. Another variant in the same area appears to be made of soft material, but in actuality is quite sturdy. In Dinosaur Land, ? Blocks are made of a special, extra-shiny material that's proven to be shock resistant. The "?" symbol also prefers to rotate around the block's sides.

The purpose of the ? Block is its ability to store a wide variety of objects, including living beings. The exact limit as to how much can be stored inside a ? Block is unknown, but it's important to note that it can store a large number of things. After a ? Block has been emptied of its contents, the block turns a brown color with its "?" icon missing.

The scientists at Woohoo Hooniversity have taken the task of researching the many "Blocks of Nostalgia", likely inspired by Mario's adventures as they've taken to naming the boxes in reference to Mario's past adventures. Part of this research is by recreating prototype versions and developing new types of blocks.