This unusual vessel is made of a U-shaped container and a sheet of clay modeled as a deity mask that is startling in its power: pierced eyes glare from the shadow of a muscular brow; the chin juts aggressively; and the part-bird, part-jaguar mouth opens in a shriek. This may be the face of the Olmec rain deity, the inspiration for much Olmec ritual and many accomplished works of art. The vessel may come from a grave or a buried offering.