Claus Meyer / Parrot Snake (Leptophis ahaetulla) with mouth open in defense display, Caatinga ecosystem, Brazil

ZSSD / Twig Snake (Thelotornis capensis) flicking tongue, native to South Africa, San Diego Zoo, California

ZSSD / Twig Snake (Thelotornis capensis) view of head from above, native to South Africa

ZSSD / Twig Snake (Thelotornis capensis) view of head from above, native to South Africa

Pete Oxford / Vine Snake (Oxybelis brevirostris) aggressive display, Choco rainforest, northwest Ecuador

Michael & Patricia Fogden / Twig Snake (Thelotornis capensis) inflating throat in threat display, South Africa

Michael & Patricia Fogden / Twig Snake (Thelotornis capensis) inflating throat in threat display, South Africa

Michael & Patricia Fogden / Twig Snake (Thelotornis capensis) camouflaged in tree, South Africa

Claus Meyer / Colubrid Snake (Chironius sp) portrait, Amazon ecosystem, Brazil

Claus Meyer / Bird Snake (Thelotornis sp) camouflaged among tree leaves, Amazon ecosystem, Brazil

Michael & Patricia Fogden / Vine Snake (Oxybelis argenteus) hanging from tree, Amazon rainforest, Ecuador

Michael & Patricia Fogden / Vine Snake (Oxybelis brevirostris) on Heliconia (Heliconia trichocarpa) rainforest, Costa Rica

Claus Meyer / Parrot Snake (Leptophis ahaetulla) hanging from tree showing defensive display, Caatinga ecosystem, Brazil

Claus Meyer / Parrot Snake (Leptophis ahaetulla) in threat display, Caatinga ecosystem, Brazil

Claus Meyer / Bird Snake (Thelotornis sp) camouflaged among leaves, Amazon ecosystem, Brazil

Mark Moffett / Vine Snake portrait, La Selva, Costa Rica

Mark Moffett / Vine Snake portrait, La Selva, Costa Rica

Mark Moffett / Vine Snake and herpetologist Ted Papenfuss, Tam Dao National Park, Vietnam

Mark Moffett / Vine Snake on branch, Peru

Mark Moffett / Vine Snake (Natrix trianguligera) face, Tam Dao National Park, Vietnam

Mark Moffett / Vine Snake and herpetologist Ted Papenfuss, Tam Dao National Park, Vietnam