8 Black Snakes in Texas: One is Venomous!

Written by Kristen Holder
Updated: April 7, 2023
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Key Points:

  • There are eight different types of black snakes in Texas, but only one is venomous.
  • The venomous snake found in Texas is the cottonmouth.
  • One of the non-venomous snakes is the Gulf Swamp Snake.

Snakes are often portrayed as aggressive, but almost all snakes retreat at the sight of humans. They’ll only attack if they’re cornered or surprised. However, if this attack comes from the one venomous snake on our list of 8 black snakes in Texas, you’re in trouble.

While snakes seem scary, they play a valuable role in local ecosystems. They keep rodent populations down, which in turn keeps the rates of certain diseases in check. That’s because rodents are known vectors for certain diseases in humans, and snakes are vital in the natural eradication of these pests.

Regardless, that doesn’t mean that all snakes are harmless and all bites will be avoided. As such, it’s best to know what kind of snakes you’ll encounter in the wild in Texas.

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Since the deadly cottonmouth is making our list of 8 black snakes in Texas, it’s important to remember the defining characteristics of its non-venomous neighbors so you aren’t unwittingly killing snakes that are good for the environment.

8 Black Snakes in Texas

A black rat snake slithering over a large rock
The black rat snake is a type of snake found in Texas.

©Psychotic Nature/Shutterstock.com

These are 8 of the black snakes in Texas:

  1. Western Cottonmouth
  2. Gulf Swamp Snake
  3. Mississippi Green Water Snake
  4. Plain-Bellied Water Snake
  5. Broad-Banded Water Snake
  6. Graham’s Crayfish Snake
  7. Florida Redbelly Snake
  8. Texas Indigo Snake

1. Western Cottonmouth

Western Cottonmouth
Western cottonmouths are among the venomous snakes in Texas.

©Psychotic Nature/Shutterstock.com

Western cottonmouths are highly venomous pit vipers. They’re also called water mocassins because they are semi-aquatic. They especially like slow-moving water waves, like that found in lakes.

Their mouths, which they bare open when threatened, are as white as cotton, which is how they earned their most common name. They are thick snakes that are generally 2 to 4 feet in length, though the longest ever recorded was over 6 feet long.

Males have a larger home range than females, though both stick close to water no matter where they travel. Western cottonmouths like to chow down on fish, other snakes, frogs, small mammals, and birds.

Their heads are triangular and sometimes adorned with identifiable bands of color. More often than not, these snakes appear all black.

This is the most important snake on our list of 8 black snakes in Texas since it’s venomous, and most of the other snakes on our list are mistaken for this species.

That isn’t to say that they’re famous for biting people. Less than 1% of snake bites annually are attributed to cottonmouths.

2. Gulf Swamp Snake

Also known as gulf crayfish snakes, gulf swamp snakes primarily eat crayfish. They do so by eating their victims alive, with the heads going in last. They coil around the crayfish, chomp on its abdomen a few times to immobilize it, then orient it, so the tail can be swallowed first. This is so that the legs of the crayfish will pull forward for easier consumption.

These snakes are found in the lowlands of eastern Texas.

3. Mississippi Green Water Snake

Mississippi Green Water Snake
Mississippi green water snakes often appear black from afar.

©Ryan M. Bolton/Shutterstock.com

Mississippi green water snakes grow up to 4.5 feet in length, and they’re generally dark or olive green in color. They often appear black, which is why they made it onto our list of 8 black snakes in Texas.

These snakes are like slow-moving water. Swamps, streams, ponds, and lakes are perfect for them. They aren’t venomous, but they will strike if threatened.

4. Plain-Bellied Water Snake

Plain-Bellied Water Snake - Yellow Belly Water Snake
Plain-bellied water snakes live in the same habitats as cottonmouths.

While plain-bellied water snakes live in the same habitats as cottonmouths, they are distinctly different snakes. They get their moniker from their plain orange bellies. They’re fond of salamanders, fish, and frogs.

Plain-bellied water snakes grow to a bit over 3 feet long. They’re thick-bodied, and their colors vary. One of their more common colors is black, which makes them black snakes in Texas.

These snakes highly prefer permanent water sources like rivers, streams, swamps, and ponds. Cottonmouths will make a meal of these snakes.

5. Broad-Banded Water Snake

Broad-banded water snakes will bite if you try to handle them.


Broad-banded water snakes hang out near the water, as their name implies. They like to chow down on the same foods as other water snakes, including insects, salamanders, crayfish, fish, toads, frogs, mice, and mammals.

Their vision is terrible, so they prefer to be active in the dark of the night. These snakes are aggressive if cornered, but they’re non-venomous. These water snakes will repeatedly bite if you try to handle them.

6. Graham’s Crayfish Snake

Graham’s Crayfish Snake
Graham’s crayfish snakes are commonly seen around ponds and other slow-moving bodies of water.

©Rusty Dodson/Shutterstock.com

Similar to gulf swamp snakes, Graham’s crayfish snakes also eat crayfish. They’re dull brown to black. Due to their dull black color, they are considered one of the 8 black snakes in Texas.

Since they like crayfish, they hang out where the crayfish hang out. They like slow streams, lakes, and brackish ponds.

7. Florida Redbelly Snake

Florida Redbelly Snake
Even though their name says “Florida,” Florida redbelly snakes live in Texas.

©Laura Gaudette / CC BY 4.0 – License

Florida redbelly snakes are little snakes coming in at under 10 inches long. Their bodies are thin, and their bellies are bright red.

Ponds and swamps are their jam. They’re nocturnal, and they like to eat earthworms and slugs.

Generally, these snakes aren’t black, but enough individuals have reported them black that the Florida redbelly snake deserves to be mentioned. Young snakes are darker than adults.

8. Texas Indigo Snake

Texas indigo snakes are large-bodied, very long snakes with a base color of iridescent black scales and brown speckles.
Texas indigo snakes are very long snakes with a base color of iridescent black scales and brown speckles.

©Joe Farah/Shutterstock.com

Ten snake species are protected in Texas, including Texas indigo snakes. These snakes are technically dark blue, but they look so dark sometimes that they appear black.

They grow to an average of 6 feet long, and they’re able to eat rattlesnakes. They can take on rattlesnakes because they’re partially immune to their venom.

Texas indigo snakes’ food is taken down by force, and they’ll eat anything that they can capture. You’ll see them out hunting during the day, though sometimes they burrow under old logs and hang out there.

They’re found in central and south Texas. They also have an iridescence to them, and they’re speckled with brown. The rest of their body is black, except for a pinkish stomach.

Texas indigo snakes are a popular pet choice, as they’re not aggressive. When they bite, though, it hurts.

Other Reptiles Found in Texas

eastern fence lizard sitting on wood
Texas is home to a few different species of spiny lizards.

©Isabel Eve/Shutterstock.com

Texas is home to a diverse range of reptile species, with many of them exhibiting fascinating characteristics and behaviors. From the iconic Texas horned lizard to the elusive western diamondback rattlesnake, these reptiles play important roles in the state’s ecosystems and provide valuable opportunities for scientific research and education.

With that said, here is a short list of other reptiles found in Texas:

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8 Black Snakes in Texas: One is Venomous!

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About the Author

I'm a fact-driven creative with a love of history and an eye for detail. I graduated from the University of California, Riverside in 2009 with a BA in Art History after a STEM-focused high school career. Telling a complex story with real information in a manner that's easy to digest is my talent. When I'm not writing for A-Z Animals, I'm doting on my 3 cats while I watch documentaries and listen to music in Romance languages.

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