Texas coral snake (Micrurus fulvius tener) - The coral snake is by far the most common venomous snake in urban and suburban areas of the Rio Grande Valley. It is easily recognized by the fact that its red and yellow bands touch. (However, this rule does not work in many parts of Mexico.) Although coral snakes are inoffensive and seldom bite, they are quite capable of biting a human being and their neurotoxic venom is more lethal than a rattlesnake's.