Boa constrictor imperator
Its a nonvenomous boa subspecies found in Central America and northern parts of South America. The appearance of this snake varies greatly depending on the specific locality. Unfortunately it is a favorite among collectors, and there are fears that they are almost extinct in the wild.
The local zoo call me when they perform biometry processes with animals, so they can also see their progress through photographs. (they could do that, but they know I enjoy doing this :) )