From the clear, oxygen-rich waters of streams and rivers across eastern North America emerges a truly formidable insect – Corydalus cornutus, commonly known as the Eastern Dobsonfly. While the adult is a short-lived, somewhat clumsy giant of the night, its larval form, the “hellgrammite,” is a fearsome aquatic predator whose intimidating appearance and powerful mandibles make it a legendary inhabitant of freshwater ecosystems and a prized bait among anglers.