glass-snake

from The Century Dictionary.

• noun A large limbless lizard, Ophiosaurus ventralis, abundant in the southern United States: so called from its general resemblance to a snake and the extreme fragility of its tail.
• noun A lizard of the genus Pscudopus, as P. pallasi, inhabiting Europe and Asia. P. gracilis of India is the Khasya glass-snake, without even the rudiments of limbs.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Zoöl.) A long, footless lizard (Ophiosaurus ventralis), of the Southern United States; -- so called from its fragility, the tail easily breaking into small pieces. It grows to the length of three feet. The name is applied also to similar species found in the Old World.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun snakelike lizard of Europe and Asia and North America with vestigial hind limbs and the ability to regenerate its long fragile tail