Nightmare Chunk

Nightmare Chunks are stones that appear in the Dream World in Mario & Luigi: Dream Team. When Antasma was near defeat before the events of the story, he used his remaining power to shatter the Dark Stone and imprison the Pi'illos in Nightmare Chunks. This put them in a state of eternal sleep. However, Mario and Dreamy Luigi can easily break the Nightmare Chunks in-game by jumping into them from below or hitting them with their hammers to free the imprisoned Pi'illo. They can be imprisoned in one or more Nightmare Chunks, depending on the Pi'illo, in which case all Nightmare Chunks must be broken.

The first Pi'illo freed was Prince Dreambert, the ruler of the Pi'illos. After freed from his own Nightmare Chunks, he attempted to free his fellow Pi'illos from their prisons, but found he could not break the Chunks. He enlisted the help of Mario and Luigi to find the remaining Pi'illos and rescue them.