Snake Block

Snake Blocks are Blocks found in Super Mario World and New Super Mario Bros. In both games, they are a set of blocks that start out as a normal platform that begins to move when stepped on by Mario or Luigi. They resemble normal Used Blocks in Super Mario World, and are bright green in New Super Mario Bros. Snake Blocks track across the screen, turning left, right up or down as they follow a pre-determined course over obstacles such as a wide pool of lava, a bed of spikes or a bottomless pit. Mario must continue to move when on these blocks or they will slide out from under his feet and he will fall to his probable doom.

A similar Snake Block called the Ice Snake Block appeared in New Super Mario Bros. Wii.