Amphisbaenians, also known as "worm lizards," are part of the taxon Squamata. Like other squamates (i.e., lizards and snakes) amphisbaenians have elongated bodies, skin that sheds in large fragments, a pair of hemipenes (male copulatory organs), and other typical squamate features.

Amphisbaenians have a worm-like appearance. Like worms, amphisbaenians have elongated bodies, no limbs (except for members of the Family Bipedidae, including the five-toed worm lizard), and are adapted for living in the soil. In addition, cutaneous grooves give amphisbaenians a ringed look similar to the annulated bodies of worms. Amphisbaenians in the wild are often unseen as they spend most of their time under leaf litter or in soil. Only one species, the Florida worm lizard, is native to the United States.