Nick Garbutt / Amazon tree boa (Corallus hortulanus) coiled around tree trunk in lowland rainforest understorey. Manu Biosphere Reserve, Peru.

Lucas Bustamante / Amazon tree boa (Corallus hortulanus) juvenile, curled up, Cuyabeno, Sucumbios, Ecuador.

Lucas Bustamante / Juvenile of Amazon Tree-Boa (Corallus hortulanus) in defensive position. Yasuni National Park, Orellana, Ecuador.

Daniel Heuclin / Amazon tree boa (Corallus hortulanus) coiled up in branch, captive from South America. Venomous species.

Daniel Heuclin / Amazon tree boa (Corallus hortulanus) coiled up in branch, captive from South America. Venomous species.

MYN / JP Lawrence / Amazon tree boa (Corallus hortulanus) San Jose de Payamino, Ecuador Meetyourneighbours.net project

Cyril Ruoso / Anaconda (Eunectes murinus murinus) Pacaya-Samiria National Reserve, Amazon, Peru.

Pete Oxford / Common Tree Boa (Corallus hortulanus) yellow morph in defensive posture, native to South America

Pete Oxford / Common Tree Boa (Corallus hortulanus) juvenile in defensive posture, native to South America

Pete Oxford / Common Tree Boa (Corallus hortulanus) juvenile, native to South America

Daniel Heuclin / Amazon tree boa (Corallus hortulanus) close up of face, baring fangs, French Guiana

Daniel Heuclin / Amazon tree boa (Corallus hortulanus) close up of eye, French Guiana