All lizards have legs. They do have external ear openings and moveable eyelids like other lizards. Snakes have neither external ear openings nor moveable eyelids. Snakes don't have bones. Large pythons, boas and anacondas may have 300-400 pairs of ribs.
All snakes are venomous.
Out of the 110 species of snakes in the United States, only 20 are venomous. Venomous insects, fish, and poisonous plants pose more of a threat to humans than do venomous snakes. In fact, more people die each year of bee stings than snake bites. If you encounter a snake in the wild that you are not sure about, leave it alone and it will leave you alone. Snakes can hypnotize you with their stare.