Crotalus durissus (Tropical Rattlesnake, Schauerkapperschlange)
Crotalus durissus is a venomous rattlesnake species found in South America. The most widely distributed member of its genus, this species poses a serious medical problem in many parts of its range. Currently, eight subspecies are recognized, including the typical form described here. [Wikipedia]
It is maybe one of the most dangerous rattlesnakes, very nervous and has a strong venom. It was indeed very nervous when I photographed it in Salzburgs "Haus der Natur".
Canon 5D with Sigma 105/2,8 Macro
1/60s f/5 ISO 1250 -4/3 EV
through glass, no tripod, no flash