Light Block

A Light Block is a type of block appearing in the New Super Mario Bros. sub-series.

New Super Mario Bros. Wii
Light Blocks first appear in New Super Mario Bros. Wii, exclusively in. These blocks appear as moving nearly-invisible blocks at first (which look similar to Empty Blocks from Super Mario World), but if Mario or any other character hits a nearby ? Switch, the blocks temporarily glow and keep moving. These blocks can be used for both lighting the way and means of transportation.

New Super Mario Bros. U / New Super Luigi U / New Super Mario Bros. U Deluxe
Light Blocks reappear in New Super Mario Bros. U, New Super Luigi U, and their port, behaving exactly the same as in previous appearances. They appear in Light Blocks, Dark Tower in the former and in Light-Up-Lift Tower in the latter.

Other appearances
In the Super Mario Mash-up in Minecraft, Redstone Lamps are replaced by Light Blocks.