Northern Cottonmouth vs. Mississippi Green Watersnake

Two heavy, dark, nearly plain snakes that share the cypress swamps of the southern tip. The Cottonmouth has a broad, blocky head much wider than its neck (a watersnake's head is narrow), a dark band through the eye edged above with a pale line, a vertical pupil and a pit between the eye and the nostril. The Mississippi Green Watersnake has a round pupil, no eye band, and a row of small scales between the eye and the upper lip, which no other Illinois snake has; its chin and throat are yellow and its belly is dark with pale half-moons.

Photographs via iNaturalist under Creative Commons licences; the photographers are credited on the sheet.

More comparisons

• Northern Cottonmouth vs. Common Watersnake
• Northern Cottonmouth vs. Plain-bellied Watersnake
• Northern Cottonmouth vs. Diamondback Watersnake
• Northern Cottonmouth vs. Eastern Copperhead
• Banded Watersnake vs. Northern Cottonmouth
• Broad-banded Copperhead vs. Northern Cottonmouth
• Brown Watersnake vs. Northern Cottonmouth
• Florida Cottonmouth vs. Northern Cottonmouth
• Florida Green Watersnake vs. Northern Cottonmouth
• Mississippi Green Watersnake vs. Common Watersnake
• Mississippi Green Watersnake vs. Plain-bellied Watersnake
• Mississippi Green Watersnake vs. Diamondback Watersnake
• Banded Watersnake vs. Mississippi Green Watersnake
• Glossy Swampsnake vs. Mississippi Green Watersnake
• Saltmarsh Snake vs. Mississippi Green Watersnake

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