Giant marshmallow candy - I think this would make a perfect pillow, mushy and sweet.
And yes, the framed ones are made of real Peeps.
Part of the 11th Annual Sculpture Conference in 1980, which included the installation of 500 pieces of public art throughout Washington, D.C., “The Awakening” is a cast aluminum sculpture depicting the arousing of a bearded giant. The piece is actually five separate ones – head, hand, outstretched arm, bent knee and foot – arranged in such a fashion as to suggest that the giant is breaking free from the confines of the earth. (Source: http://www.nationalharbor.com/Events.aspx?id=658)