Black spiny-tailed iguana

"The largest members of the genus Ctenosaura, males are capable of growing up to 1.5 meters (4 ft 11 in) in length and females slightly shorter at 1 meter (3 ft 3 in). They have a crest of long spines which extends down the center of the back. Although coloration varies extremely among individuals of the same population, adults usually have a whitish gray or tan ground color with a series of 4–12 well-defined dark dorsal bands that extend nearly to the ventral scales."