The fruit bodies of "Calvatia craniiformis" grow to dimensions of tall by wide, and have a form ranging from pear-shaped, to flattened-spherical, to obovate (roughly egg-shaped), to tunicate (like an inverted cone). At the bottom is a thick, often crumpled base attached to a cord-like rhizomorph, which is often encrusted with surrounding soil. The rhizomorphs are well developed, and when cut into longitudinal section, reveal three distinct tissues: an outer cortex, a subcortical layer, and a central core. The thin and fragile exoperidium (the outer layer of "skin") is whitish-gray to gray, and initially smooth before becoming areolate (divided by cracks into discrete areas). The base extends up one-third to one-half way into the puffball (where it becomes the columnella) tapering to a point. The gleba is initially whitish, and then yellow-green, and finally brownish-green in older specimens with mature spores.