Ingo Arndt / Carpet python snake (Morelia spilota variegata) hatching from egg, Australia. Captive.

Ingo Arndt / Carpet python snake (Morelia spilota variegata), hatching from egg, Australia. Captive.

Chris Mattison,Chris Mattison / Rubber Boa (Charina bottae) in defensive posture, raising tail to mimic head. California, USA, November.

Michael D. Kern / Python (Morelia amethistina) captive from Australasia

Daniel Heuclin / Dumeril's Ground Boa (Acrantophis dumerili) against white background. Endemic to Madagascar.

John Cancalosi / Boa Constrictor (Boa constrictor) shedding skin from head. Guanacaste National Park, Costa Rican tropical rainforest.

John Cancalosi / Boa Constrictor (Boa constrictor) shedding skin from head. Guanacaste National Park, Costa Rican tropical rainforest.

Anup Shah / African rock python (Python sebae) Masai Mara National Reserve, Kenya

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

Steve Nicholls / Skeleton of a Python (Python sp)

Juergen Freund / Black-headed python (Aspidites melanocephalus) perched on a tree branch overlooking the Australian outback. Queensland, Australia, February

Pete Oxford / Amazon Tree Boa (Corallus hortulanus) in rainforest, Iwokrama Reserve, Guyana, digitally manipulated image