In image 4 we see Chalchiuhtotolin, the Jeweled Bird, the turkey god. This figure is plainly a disguise for Tezcatilpoa, whose sandaled feet protrude from the bird's claws, whose face appears inside the bird's beak, and whose smoking mirror and night-sky headdress appear at the top of the bird's head. Turkeys are fascinating birds to observe. Their head and necks are naked, full of folds, caruncles, and fissures, displaying many colors from bright primaries through subtle pastel shades. In some instances, the color of the wattles darkens from morning till noon, then lightens as the sun sinks toward the western horizon. They have long fleshy red ornaments over their bills. They stage elaborate courtship rituals including lavish feather displays, and create a type of music with them to accompany their mating songs, songs which suggest gurgling water. Their dances shade into battles, particularly at matin time. To the Aztecs the deified bird presided over ritual self-mortification. The ornament over the beak was emblematic of blood sacrifice and the head and neck skin suggested evisceration. The bird, then, was a walking sacrifice, whose rituals could be copied by humans. In this image the god utters a stream of jeweled water that flows into a jar. Jeweled or precious water is a complex concept in Aztec religion, expressing the economic relations between humans and gods. The term "precious water" was a kenning for the blood humans must shed to keep the gods alive; water is the blood of the gods, given to humans as the basis of their sustenance. This image summarizes the exchange of these two types of water. Generally, Tezcatlipoca manifests himself as a dark and sinister god. We could see the blood letting in the present image as an expression of dreadful malevolence, but the Aztecs certainly did not. In this case his nature is modified by the turkey form he here assumes. In Christian terms, Chalchiutotolin's powers can be seen as a type of grace. Although Tezcatlipoca could tempt humans into self-destruction, when he assumed his turkey form he could also cleanse them of contamination, absolve them of guilt, and mitigate their otherwise inexorable calender-based fate - no other god could perform this last function. The harrowing implied in this image, then , is a form of catharsis and liberation rather than a form of torture, presided over by the bird whose head is covered with the jewels of sacrifice, who does a stately and fascinating dance, and who sings a song promising fructifying water and release from pain, songs and dance that humans must copy to achieve these blessings.