WHAT AM I?

I hiss, but I don't lay eggs, When I am a female I can get to 2. 1 and 3.1 metres long, When I am a male I can get to 1. 8 and 2. 4 metres.  I am blue, cream, black, white, green and yellow.  I have scales; I eat rodents but don't have fangs; I slither up trees and I live in America

               
                     
                          
                               
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