Daniel Heuclin / Close up of skin of Rainbow boa (Epicrates cenchria cenchria) captive, from French Guiana

Andrew Snyder / Rainbow boa (Epicrates cenchria showing iridescence on head, Iwokrama, Guyana.

Lucas Bustamante / Rainbow boa (Epicrates cenchria) wound round branch over water, Tambopata, Madre de Dios, Peru.

Michael D. Kern / Rainbow boa (Epicrates cenchria cenchria) captive. Small repro only

Thomas Marent / Rainbow Boa (Epicrates cenchria) juvenile, Amacayacu National Park, Leticia, Colombia

Pete Oxford / Rainbow Boa (Epicrates cenchria cenchria) shed skin, native to Central and South America

Pete Oxford / Rainbow Boa (Epicrates cenchria cenchria) young, native to Central and South America

Pete Oxford / Rainbow boa (Epicrates cenchria cenchria) juvenile, Amazon, Ecuador. Captive, occurs in Central and South America.

Philippe Clement / Cuban boa (Epicrates angulifer) resting. Captive, occurs in Cuba and the Bahamas.

Philippe Clement / Cuban boa (Epicrates angulifer) resting. Captive, occurs in Cuba and the Bahamas.

MYN / Andrew Snyder / Brazilian Rainbow boa (Epicrates cenchria), Berbice River, Guyana, September. Meetyourneighbours.net project.

MYN / Andrew Snyder / Brazilian Rainbow boa (Epicrates cenchria), Berbice River, Guyana, September. Meetyourneighbours.net project.