Tikal caches frequently contain a wide variety of marine materials such as shells, fish bones, and stingray spines (Coe 1990; Maxwell 1996). Beyond the possible use of stingray spines as bloodletters, however, little attention has been given to the role of these objects in ritual. Numerous caches contain the remains of toxic animals, including stingrays, porcupine fish, cone shells, and potentially toxic corals and sponges. Intriguingly, these objects are found in the greatest frequencies dating to the period from a.d. 562 to 695—known as the Tikal hiatus—beginning immediately following the defeat of Tikal by Caracol and ending with the ascension of Ruler A. It is proposed toxic marine objects were employed in rituals at Tikal and these rituals were most important during the hiatus period.