Legless lizards are normal lizards that lost their legs. Legless lizards didn’t just kick off their legs and slither away one day. Over millions of years, the animals developed smaller and smaller limbs until, eventually, their legs and arms disappeared. This kind of change, which is called evolution, often happens over long periods of time.
Legless lizards are not snakes. Rather, functional limblessness has evolved independently perhaps a dozen times in the squamate reptiles — lizards, snakes and amphisbaenids, or worm lizards — suggesting that the body plan offers many advantages.
Snakes are just the most successful of the lineages that went limbless, radiating over time into roughly 3,000 species that have exploited nearly every available habitat, from the treetops to the open ocean to the ground beneath our feet. The most common, and probably most notable, of these are eyelids and externally opened ears.
Snakes don’t have them. Snakes have relatively short tails. There are hundreds of legless lizard species found around the world. Some are skinny and super snakelike, while others are chunks,with bulky, legless frames.