Komodo dragon

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A large monitor lizard (Varanus komodoensis) native to Indonesia. It is the largest living lizard, sometimes growing to a length of 3 meters (10 feet).

Wiktionary

1. n. An endangered species of monitor lizard native to certain Indonesian islands east of Java. It is the world's largest lizard, growing to 10 feet or 3 meters. It is known for its ability to kill prey with its septic saliva; the resulting septicemia can kill so quickly that it was once suspected the lizard was venomous.

WordNet 3.0

1. n. the largest lizard in the world (10 feet); found on Indonesian islands