The fully polychrome chacmool found "in situ" in the Great Temple was associated with Tlaloc by its placement on the Tlaloc half of the double pyramid. A further Aztec chacmool was described in the 19th century; it is of uncertain origin but stylistically it is typical of Tenochtitlan. It is sculpted on the underside with aquatic imagery and the figure wears a goggle-and-fangs Tlaloc mask. Spanish observers reported the great quantity of human sacrifices during important ceremonies at the Great Temple and the chacmool was probably used during these rituals to symbolise the sacrificed captives as well as receive their blood.