A plastic water cooler is a type of container that would typically be taken camping or on a picnic.
In 1985, some children found a plastic water cooler floating in Onondaga Lake. (MM: "The Beginning & the End") After police and FBI arrived, the cooler was dragged out of the water and was immediately opened while Peter Watts, a member of the FBI, watched. (MM: "The Fourth Horseman") Inside the container was the tiny body of a four-month-old baby boy who had no head or arms, just so whoever could fit the body inside. (MM: "The Beginning & the End")
In 1997, Watts told Frank Black about this incident, mentioning that the cooler had been found by children, and, in 1998, Watts vividly recalled having watched the container be dragged out of the water and opened. (MM: "The Beginning & the End", "The Fourth Horseman") Soon thereafter, Watts had recurring vivid recollections of having witnessed the cooler be opened, while he started to investigate an outbreak of the Marburg Virus with Frank Black. (MM: "The Fourth Horseman")
- Although the only description of this type of container in episode dialogue comes from Watts referring to it as a "cooler" when telling Frank Black about the incident, the same container is specifically described as a "plastic water cooler" in the script of "The Fourth Horseman".