The catoblepas is described in Roman texts
from the ﬁrst century C.E.as an imaginary animal that looks something like a bullor bison with a large, heavy head and along, shaggy mane. These creatures are also listed in medieval bestiaries, the encyclopedic collections of both real and imaginary animals.
The weight of its massive head is what kept the catoblepas from being able to look upwith its bloodshot, red eyes. Its name meant “that which looks downward” in Greek. Once it was able to lift its head, however, thecatoblepas’s glance was deadly. Since it atemostly poisonous plants, its breath was also lethal.
The Roman historian and naturalist Pliny the Elder mentioned the creature in his Natural History. Pliny claimed that the home range of the catoblepas was near a spring in Ethiopia that was the source of the Nile River. It was Pliny who ﬁrst claimed that the gaze of the catoblepas was deadly.
The writings of another Roman author, Claudius Aelianus, provide a fuller description of the catoblepas than Pliny’s work. In On the Nature of Animals, Aelianus claimed that the creature was about the size of a domestic bull, with a heavy mane, narrow, bloodshot or red eyes, and shaggy eyebrows. In Aelianus’s description, the animal’s gaze was not lethal. It was in this account that the catoblepas was described to have poisoned breath.
Descriptions of the catoblepas make it sound either like a gnu, the large African antelope with a head resembling that of an ox, or a North American bison. There are North American tribal tales about why the bison never looks up, most of which center on a curse placed on it by the trickster hero Coyote. But the comparison ends there. Neither gnus nor bison possess the poisonous glance or breath of the catoblepas.