Reptiles are cold-blooded vertebrates. meaning that they must regulate their body temperature behaviorally, either by basking in the sun to warm themselves or by hiding under cover to keep cool. Some are legless, but those with legs have claws. Some (such as lizards) look superficially similar to some amphibians (such as salamanders), however reptiles are dry-skinned.

There are four orders within the Reptilia class: the Testudines (turtles), the Crocodilia (crocodilians), the Rhynchocephalia (Tuataras, spiny-backed lizard-looking reptiles found only in New Zealand), and the Squamata (snakes and lizards). The suborders, clades, and superfamilies within the taxonomy/phylogeny of the Squamata order is complex, but as the order is so large (with some 10,900 species across 60 families), it will be divided up on this page into selected higher classifications (representing only families with species found in the Central Alabama region where Columbiana and Harmon Park are located.