A cuauhxicalli or quauhxicalli (Nahuatl pronunciation: [kʷaːʍʃiˈkalːi], sounding somewhat kwah-wh-shee-KAL-ee, meaning "eagle gourd bowl") was an altar-like stone vessel used by the Aztecs to hold human hearts extracted in sacrificial ceremonies. A cuahxicalli would often be decorated with animal motifs, commonly eagles or jaguars. Another kind of cuauhxicalli is the Chacmool-type which is shaped as a reclining person holding a bowl on his belly.
Jaguar shaped Cuauhxicalli in the National Museum of Anthropology of Mexico
Cuauhxicalli in the shape of an eagle, from the Templo Mayor
Video of a cuauhxicalli, National Museum of Anthropology of Mexico