indigo snake

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

• noun Any of several bluish-black nonvenomous snakes of the genus Drymarchon found from the southern United States to northern South America.

from The Century Dictionary.

• noun The gopher-snake, Spilotes couperi.

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

• noun large dark-blue nonvenomous snake that invades burrows; found in southern North America and Mexico