Copperhead
Tan with darker hourglass bands. The one most people run into; bites are common but rarely deadly.
Wildlife / There's a snake
Take a breath. The vast majority of Texas snakes are non-venomous and harmless - they eat rats and mice and want to avoid you. Of the state's roughly 76 snake species, only about 15 are venomous. Here's how to think about it without panicking.
On average, only 1 to 2 people in Texas die from snakebite each year - but a venomous bite is still a true emergency.
Tan with darker hourglass bands. The one most people run into; bites are common but rarely deadly.
Dark and thick-bodied, near water in the eastern half of the state; shows a white mouth when threatened.
Several kinds (the western diamondback is the big one). Usually - not always - they buzz a warning.
Small and brightly ringed - the only Texas snake with red and yellow bands touching. Shy and rarely seen, but with strong venom.
Don't trust the old shortcuts. TPWD warns that none of the popular tells - a triangular head, 'cat-eye' pupils, a heavy body - are reliable, because harmless snakes can share them. The coral snake rhyme ('red touch yellow, kill a fellow; red touch black, friend of Jack') works for typical Texas coral snakes, but it isn't foolproof and harmless look-alikes exist. The safe rule: leave any snake you can't positively identify alone.
Those old "remedies" - cutting, sucking, ice, tourniquets - cause harm. Skip them and get to a hospital.
Snakes follow food and shelter. Clear brush, woodpiles, rock piles, tall grass, and junk near the house, and watch your hands and feet around rocks, logs, and sheet metal. A snake in the yard will usually move on if you give it space; for one stuck in a garage or house, call a local wildlife removal pro. Most snakes are nongame (you'd need a hunting license to kill one, and a few species are specially protected) - and even a harmless bite can get infected, so don't handle wild snakes.
Official sources
Snakebite first aid comes from Texas DSHS (the health department) and the Texas Poison Center Network; snake identification and safety come from TPWD. For a bite, professional care comes first.
Caution: This is general first-aid information, not a substitute for medical care. For any venomous bite, call Poison Control or 911 and get to an emergency room.