At the suggestion of his daughter Laura, a trained potter, Grass turns to modeling with clay in the 1980s. He emphasizes the primordial quality of the material in his picture book Gebrannte Erde (Burnt Earth) (2002): »Moist clay, churned and well-kneaded, moldable into vessels, idols, reliefs, and hollowware, will slightly shrink from air-drying, shrink again in the pottery kiln, and acquire a different color in intense heat: brick red, ocher yellow, peat black. Clay as can be found in many places has from time immemorial served the oldest craft well and – both whole and shattered – gives evidence of the beginnings of every culture.«

One of Grass's first terra-cotta sculptures is the Stone Age goddess Aua, who, according to the novel The Flounder (1977), brings fire to humankind. The female figures in the novel represent the stronger sex and the origin of life, from which men try to liberate themselves. In the novel, the goddess Aua has three breasts with which she also feeds the men. With the liberation of men, the third breast disappears. Grass seizes upon this idea in his sculpture, which is worked as a relief: The head, the arms, and the legs are missing, the female sexual characteristics, such as the voluptuous body and the wide hips, are thereby emphasized. By reducing the female body to its fertility features, the sculpture with is large breasts, voluminous curves, and the emphasis on the pubic region is reminiscent of archaic female statuettes from the later Paleolithic.

Unlike the Stone Age figurines, however, Grass's goddess has by far more balanced contours and a smooth-finished surface, thereby giving the impression of a Greek torso as well. Grass thus merges beauty ideals for the female body from the Stone Age and from the Occident and creates an entirely unique mythological type of woman.