Dreamy Pi'illo Castle is a location in the Dream World that is seen in the game Mario & Luigi: Dream Team. It is the first place visited in the dream world and is an alternate version of Pi'illo Castle. It is also where Mario first meets up with Dreamy Luigi and Prince Dreambert.
Being a dream world location, Dreamy Pi'illo Castle is basically a 2-D version of Pi'illo Castle.
Mario heads into Dreamy Pi'illo Castle after a strange, shadow creature has taken Princess Peach away. Mario runs into Dreamy Broque Monsieur and soon, Dreamy Luigi. The two follow keep exploring around the 2-D castle where they eventually corner the creature that still has Peach. The shadow creature then fights Mario and Dreamy Luigi but uses Dreamy Mario to fight them instead. Mario and Dreamy Luigi defeat Dreamy Mario, but the creature has taken Peach somewhere deeper into the dream world.