Could you help me with this phrase pls I wonder if anyone knows this phrase "Body snatchers" means. I found this in a novel. The whole paragraph is: "“Look” John said, “that’s why all the crowds.” He was pointing at a billboard welcoming delegates to the UN peace conference, which was starting on Monday. There were going to be ten thousand visitors in town. T.J. gazed up at the billboard – blacks and whites and Asians, waiving and smiling. There was something wrong about the artwork, though. The proportions and the colors were off. And the faces all seemed patsy. John muttered “Body snatchers.”"