Whittlesey is a scientist who works for the Museum of Natural History. In 1987, Whittlesey leads an expedition into the Amazon. Whittlesey secretly hopes to find evidence in the area that the Kothaga Indian tribe still exists. Instead, Whittlesey disappears. Later, it is established by Gregory Kawakita that Whittlesey was taken captive by the Kothaga and forced to eat a plant that has been infected with a strange virus that changes him into a violent animal. Whittlesey then followed his crates from the expedition back to the Museum where he haunted the halls until he is caught and killed by Pendergast.