The adult Texas rat snake is quite impressive in size. It is the largest snake in North America, with a length of more than two meters, and the longest record is 2.6 meters. It is also the longest snake in North America.

The body of the Texas rat snake is mainly yellow or brown-black, with irregular Dark or olive-colored lumpy spots. There is also a white variant, the body is snow-white, the spots disappear, and the eyes are dark red, commonly known as Bai Niangniang or Bai Niangzi, which has become a popular pet snake.