Ice Snake Block

Ice Snake Blocks are a type of Snake Block in New Super Mario Bros. Wii. They appear in World 3's castle. They function identically to normal Snake Blocks, but being made of ice, they are slippery and, throughout the entirety of World 3's castle, they move over a bottomless pit. The Penguin Suit, however, bypasses this issue.

Only two are found in the stage - the first one that leads to the checkpoint, and the second one that leads to Lemmy Koopa.

Trivia

 * Ice Snake Blocks were originally going to reappear in New Super Mario Bros. U, along with a large variant, before being removed from the game.