“ | Venice is overrun, as Rome was about to be. Cleanse it! Destroy them all! Put them to the sword! | ” |
–Mars/Ares about the katoblepones, in The House of Hades. |
Katobleps (pl. katoblepones), also known as Catoblepas, is a cow monster whose name means 'down-looker'.
The Heroes of Olympus
The House of Hades

Frank Zhang, who destroyed all of the katoblepones in Venice.
The katoblepones were accidentally imported to Venice, Italy from Africa. They eat poisonous roots that grow by the canals and have a poisonous gaze as well as poisonous breath. Frank Zhang destroyed all of them in Venice, which gave him the power of turning his enemy into a snake. He used the power to turn the last katobleps into a snake.
Description
Katobleps had the large body of a buffalo, which sat atop squat legs that resembled those of a pachyderm. A katobleps' head resembled that of a warthog, and sat atop an elongated neck that seemed ill-suited for actual support. Perhaps the most terrifying feature of these beasts were their large and deadly bloodshot eyes.
Katobleps possessed a scent that reeked of death and famine, not dissimilar to the swamp gas that filled their favored environment. The scent was reminiscent of skunk's stench mixed with foul bog vapors.