viper         
noun [ C ] uk/ˈvaɪ.pər/ us/ˈvaɪ.pɚ/
 蝰蛇(一种小毒蛇)
a small poisonous snake
  literary阴险的人 
a very unpleasant person who you cannot trust
  When I started my new job, I didn't realize that I was walking into a nest of vipers. 当我开始新的工作时,我没有意识到自己已经进了一个蛇蝎之窝。