Underground Grrrols

Underground Grrrols, or Layer Cake Desert-2, is the second course of Layer Cake Desert in New Super Luigi U. It is unlocked by completing Spike's Tumbling Desert, and its own completion will unlock Wind-Up Tower.

Layout
Luigi begins the level in desert nearby a Warp Pipe. When he enters the pipe, he will be taken to an underground area where a Pokey, a Grrrol and two ? Blocks can be found. A Hidden Block containing a Yoshi Egg in it can be found above the ? Blocks. Luigi must then walk across multiple vertices moving platforms where multiple Pokeys and Grrrols can be found. A P Switch that causes Blue Coins to appear can be found on the ceiling near two Pokeys. Afterwards, more ? Blocks and Brick Blocks can be found above semi-solid platforms. Luigi must then cross more moving platforms, where he encounters Pokeys, Grrrols and a Mega Grrrol. A Warp Pipe can be found above the Mega Grrrol. The pipe takes Luigi into the desert, where a moving platform and a Goal Pole can be found.

Star Coins

 * Star Coin 1: As soon as the player exits the pipe, they must stand on the column with a Pokey, where the Star Coin then reveals itself above.
 * Star Coin 2: The second Star Coin is found in the middle of the group of vertical squishing columns, but can only be seen at the beginning of the columns' loop.
 * Star Coin 3: The third Star Coin is located above the Grrrols near the warp pipe leading to the level's exit.

Luigi Sighting

 * A giant, pixelated Luigi is within the walls of the shortcut at the level's beginning. A P-Acorn is necessary to see it.

Enemies

 * Grrrols
 * Mega Grrrols
 * Pokeys