Snake Block

Snake Blocks, also known as Caterpillar Blocks, are blocks usually found in castle-type levels. They first appeared in Super Mario World, and re-appear in Super Mario Advance 4: Super Mario Bros. 3, the New Super Mario Bros. games, and Super Mario Galaxy 2. In all games, they are a set of blocks that start out as a normal platform and begin to move like a snake when stepped on by Mario or Luigi. They resemble normal Empty Blocks in Super Mario World, but resemble Rotating Block in Super Mario Advance 4: Super Mario Bros. 3, and are bright green in the New Super Mario Bros. games and pink in Super Mario Galaxy 2. Snake Blocks track across the screen, turning left, right up or down as they follow a predetermined course over obstacles such as a wide pool of lava, a bed of spikes, or a bottomless pit. Mario must continue to move and follow it when on these blocks, otherwise they keep moving under Mario's feet, and he may possibly fall off.

Snake Blocks get their name from the classic arcade game Snake, in which the player controls a sequence dots that resemble the snake animal.

New Super Mario Bros.
In New Super Mario Bros., Snake Blocks only appear in World 7-Castle and World 8-Tower 2.

Super Mario Galaxy 2
The Snake Blocks in Super Mario Galaxy 2 appear in the Boo Moon Galaxy, Bowser's Lava Lair, and Bowser's Galaxy Generator. In this game, they make their only 3D appearance, though they are used in the same way. It is first shown here that they can be of varying widths, instead of only one block wide, as in its previous 2D side-scrolling appearances.

Super Mario 3D Land
In Super Mario 3D Land, Flip Panels appear in some levels, with similar functions.

Super Mario Advance 4: Super Mario Bros. 3
Snake Blocks in Super Mario Advance 4: Super Mario Bros. 3 only appear in 20: A Towering Tour and 23: Vexing Doors.

New Super Mario Bros. Wii
A similar Snake Block called the Ice Snake Block appears in New Super Mario Bros. Wii. It is found in World 3's Castle, but unlike regular Snake Blocks, its icy surface is slippery, though the Penguin Suit can remedy this fact. Normal Snake Blocks are unused in New Super Mario Bros. Wii.

New Super Mario Bros. 2
Snake Blocks reappear in various levels in New Super Mario Bros. 2, where they have the same appearance they have in New Super Mario Bros.. This is the first time they are seen moving on their own. Also, this is the first time that they are not only used as platforms to cross gaps, but also as obstacles, especially in World 1-Tower. They are much more common in this game compared to the previous New Super Mario Bros. games.

New Super Mario Bros. U / 'New Super Luigi U' / 'New Super Mario Bros. U Deluxe'
Green-colored Snake Blocks reappear in New Super Mario Bros. U, but are now less commonly used than in previous games. Giant Snake Blocks also appear, being found only in Snake Block Tower.

Super Mario Maker / Super Mario Maker for Nintendo 3DS
In Super Mario Maker and Super Mario Maker for Nintendo 3DS, Snake Blocks can be reproduced by placing a long row of blocks onto a track. They also make an appearance in World 15-4 of the Super Mario Challenge of the latter version.

Super Mario Maker 2
In Super Mario Maker 2, they make an appearance as a full course element.

Mario Party 10
Snake Blocks reappear in Mario Party 10 in the minigame Snake Block Party.