Ctenosaura similis, commonly known as the black iguana or the black spiny-tailed iguana, is a species of iguanid lizard native to Mexico and Central America. It has been reported in some Colombian islands in the Caribbean Sea and Pacific Ocean, and has been introduced to the United States in the state of Florida. The largest species in the genus Ctenosaura, it is commonly found in areas such as grasslands and forests. This C. similis lizard was photographed on a tree branch near the Macal River, in Cayo District, western Belize.

Photograph credit: Charles J. Sharp