From the Super Mario Wiki, the Mario encyclopedia
The Dozing Mattress is an item that appears in Mario & Luigi: Dream Team, and one of the five Ultibed parts. It is a mattress created from the droplets of a single stalactite of Dozing Ore found in Dozing Sands. Mario and Luigi find it in a room way over to the east of the desert after they learn that Britta cannot reach the area. Before they retrieve it, Mario must enter the dream world via Dreampoint where it is really found. Once he is inside, Mario can collect the mattress.
Ultibed Manual text
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