Characteristics of the meristic features of the external morphology of young and adult snakes (the Colubridae family) of three species, namely, the grass snake Natrix natrix, the dice snake N. tessellata and the Pallas’ coluber Elaphe dione, living in the Samara region, are described. For the first time, a comparative analysis was carried out of a number of morphological characters of unevenaged snakes, namely: newborns obtained in laboratory conditions, juvenile specimens, and adult snakes captured in nature.