Eyelids: Unlike snakes, they have movable eyelids and can blink.

Ear Holes: They have visible external ear openings on the sides of their head.

Rigid Body: Their bodies are less flexible than snakes and feature a rigid, armor-like scale structure with a "lateral groove" (an expansion fold running down the side that helps them breathe and digest large meals).

The "Glass" Tail: Their tail makes up more than half their total length and can detach (drop off) in a defense mechanism called autotomy to distract predators.

Ophiosaurus apodus