The quote came from Ross Perot, who was a businessman and politician. So the quote was likely not intended to have anything to do with physical snakes, just deceitful people. This makes me think that the calendar was from a company that mass produced calendars. There are a lot of instances where quotes are automatically assigned to a picture or article with computer programs. So, I would bet that the calendar had that quote automatically assigned to it from a pool of quotes or it was from someone who just randomly assigned the quote to the calendar without thinking about it.