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10 Snakes That Look Like Cottonmouths (Pictures)

Cottonmouths, also known as water moccasins, are the only venomous species of water snake in North America. They get their name from the white lining of their mouths. Often nonvenomous snake species share the same habitat as cottonmouths, so that an encounter can be scary. In this article, we’ll discuss some species of snakes that look like cottonmouths.

Collage photo snakes that look like cottonmouths

10 Snakes That Look Like Cottonmouths

When cottonmouths feel threatened, they open their mouths wide, exposing the cotton-white inside. If you don’t heed this warning, this pit viper delivers a deadly bite as a defense and to kill prey.

The color pattern of a cottonmouth can vary to blend into wetland environments. However, their base color is usually dark brown or black and overlaid with 10 to 17 darker crossbands.

Other snake species look similar and are often mistaken for the deadly cottonmouth. However, most snakes you encounter near water are harmless and nonvenomous. Let’s look at 10 species of snakes that are sometimes mistaken for the venomous cottonmouth.

1. Diamondback Water snake

Diamondback water snake
A diamondback water snake | image by Peter Paplanus via Flickr | CC BY 2.0

Scientific name: Nerodia rhombifer

Diamondback water snakes are mostly found near water sources, fishing and hunting prey. These snakes typically sit on branches overhanging water and streams to catch fish. They come in various colors but are mostly brown with darker patches when seen from above.

They also have diamond-shaped blotches on their back. The diamondback water snake lives in the same swamp conditions as the cottonmouth and can look similar. As a result, they are often mistaken for water moccasins.

2. Plain-bellied Water snake

Plain-bellied water snake
Plain-bellied water snake | image by Northeast Coastal & Barrier Network via Flickr | CC-SA 2.0

Scientific name: Nerodia erythrogaster

The plain-bellied water snake is a nonvenomous snake whose name comes from the lack of patterning on its underside. They’re usually yellow or, less commonly, brown or red on their underbelly.They can be brown, gray, or olive green, with dark blotching down the back.

Plain-bellied water snake have similar color patterns to the cottonmouth. They feed primarily on amphibians but sometimes eat fish too. These watersnakes escape on land instead of diving into the water if threatened.

3. Queen Snake

Queensnake | image by Peter Paplanus via Flickr | CC BY 2.0

Scientific name: Regina septemvittata

The queen snake is a non-venomous semiaquatic snake native to North America. Their habitat ranges throughout the temperate regions of the continent. Queen snakes have specific habitat requirements and can only be found in areas with access to clean freshwater.

With a quick glance, you might mistake it for a cottonmouth. The queen snakes are darker brown or gray. Some look nearly black. They have a white belly that stretches around part of their sides, close to it, looking like a white stripe along both sides.

Queen snakes have a heightened sense of smell. They hunt by trailing the scent of their prey to their receptors and are very sensitive to potential danger.

4. Banded Watersnake

Banded water snake on log
Banded water snake on log | image by amdurso via iNaturalist | CC BY 4.0

Scientific name: Nerodia fasciata

The banded water snake is a mostly aquatic, nonvenomous snake. They are found in freshwater environments from Indiana to Louisiana and are often mistaken for cottonmouth. This water snake is known to charge when threatened, using its similarities to the cottonmouth as a defense.

Another defense is to release a foul-smelling musk to inhibit predators. The snake’s color can be gray, greenish-gray, or brown and has many dark cross-bandings that are barely discernible. It has flat heads and is fairly heavy-bodied.

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Banded water snakes primarily eat fish and small birds. They hibernate during the winter months, usually by hiding under logs or rocks.

5. Eastern Hognose Snake

Eastern hognose snake resting
Eastern hognose snake resting

Scientific name: Heterodon platirhinos

The eastern hognose has a wide variety of patterns, including black and grey, brown and black, and completely black. The snake could be mistaken for a cottonmouth if you’re near water.

Have an upturned snout and are known to play dead after being threatened. These snakes are rear-fanged and mildly venomous. However, their venom is usually only toxic to their prey.

However, their bite can affect your skin, leading to swelling and itching. They are generally found in drier habitats like pine forests and agricultural areas. They’re identifiable by their slightly upturned snout.

They use it to dig the earth. These snakes require loose soil for burrowing.

6. Common Watersnake

Northern water snake in freshwater
Northern water snake in freshwater | image by Hodnett Canoe Guides via Flickr | CC BY-SA 2.0

Scientific name: Nerodia sipedon

The common water snake is often confused with the venomous cottonmouth. However, this snake is non-venomous and poses no threat to humans. It is usually brown or gray, with darker bands running down its body.

It can grow to be around 3 feet long but is typically smaller. They are typically found near bodies of freshwater. Water snakes are good swimmers and often hunt for frogs and other aquatic animals.

They also dive into the water to avoid danger.

7. Brown Water snake

Brown water snake on log
Brown water snake on log | image by Kelly Verdeck via Flickr | CC BY-ND 2.0

Scientific name: Nerodia taxispilota

The brown water snake can be easily mistaken for a cottonmouth because they share a habitat and look similar. The shape of the head is how to distinguish between the two. A water moccasin has a block-shaped bulkier head.

On the other hand, the brown water snake has a sleek, narrow head. If you need to identify the snake quickly, keep in mind the cottonmouth’s wide head is to accommodate venom sacs. That’s, of course, if it doesn’t expose its white mouth to you.

8. Black Swamp snake

Black swamp snake
A black swamp snake | image by Peter Paplanus via Flickr | CC BY 2.0

Scientific name: Liodytes pygaea

Black swamp snakes are relatively small and easy to identify if you pay close attention to their belly color. They are solid black in color and have a distinct red or orange belly. These snakes are endemic to the southeastern United States.

At first glance, a black swamp snake can be mistaken for a cottonmouth, to the untrained eye. However, once you see their brightly-colored bellies it’s quite easy to tell the difference.

9. Graham’s Crayfish Snake

Graham’s crayfish snake 
A graham’s crayfish snake  | image by Peter Paplanus via Flickr | CC BY 2.0

Scientific name: Regina grahamii

Graham’s crayfish snake is found in similar environments to the cottonmouth. You can tell the difference between the two by the stripes down the side of the crayfish snake. Like the cottonmouth, Graham’s crayfish snake is dark-colored and camouflaged in the marsh environment.

As a result, their stripes will be much lighter colored, like yellow or tan. As their name implies, Graham’s crayfish snake feeds primarily on crayfish. They’re nonvenomous and harmless to humans.

10. Florida Green Water snake

Florida green water snake
Florida green water snake | image by Brandon Trentler via Flickr | CC BY 2.0

Scientific name: Nerodia floridana

The Florida green water snake is a non-venomous snake often mistaken for the venomous cottonmouth. Both snakes are brown or dark green. Florida green water snakes are commonly found in freshwater marshes and swampy areas of Florida.

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But, of course, this is the same habitat as the cottonmouth, so it’s to misidentify. The subtle difference between the two snakes is that the water snake has a narrower head than the cottonmouth. Remember, cottonmouths are pit vipers with broad heads.