king cobra

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A large venomous elapid snake (Ophiophagus hannah) of South and Southeast Asia that can grow to a length of 5.5 meters (18 feet).

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A large venomous snake found in East Asia, taxonomic name Ophiophagus hannah, the longest venomous snake in the world.

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

• noun large cobra of southeastern Asia and the East Indies; the largest venomous snake; sometimes placed in genus Naja