Birds often appeared in Ernst's collages and paintings of the early 1920s. They became a central theme in the "Dove" paintings and drawings of 1925-1926, of which Aux 100,000 Colombes (Spies no. 1025) and Oiseaux roses et bleus (Spies no. 1029) are the most noteworthy. During this period Ernst invented the technique of frottage, in which graphite is rubbed over paper placed down on textured surfaces, and the accompanying use of grattage, in which a pre-painted and partially dry canvas is vigorously scraped. These techniques enabled Ernst to devise the appearance of his own species of bird, which resembled nothing in nature and seemed to exist almost as an archetypal or transcendent avian form.

This led in 1930 to the emergence of "Loplop, Superior of Birds," who becomes an alter ego for the artist. Loplop is a messenger or prophet from the subconscious, presenting his images on "signboards" he holds up to the viewer, so that the overall composition actually consists of a picture within a picture. In the early 1930s Ernst created over 50 paintings, drawings, collages and prints which feature Loplop, whose "elongated, anthropomophic appearance was not without a curious resemblance to the artist himself." (W.S. Rubin, Dada, Surrealism and Their Heritage, New York, 1968, p. 88)