Nerodia sipedon
Often mistaken for cottonmouth. Harmless. Aggressive when handled.
FamilyColubridae
GenusNerodia
RegionNorth AmericaEastern North America
Misidentification risk
Northern Water Snake
Lethality weighted 55% (potency × yield). Clinical weighted 45% (real-world CFR).
Multiplicative scalers - amplify or reduce existing danger, can't create it from nothing.
Speed = antivenom window. Delivery = fang efficiency. Encounter = exposure × temperament.