Bullet With His Name - Fritz Leiber

In "Bullet with His Name," two alien beings have come to give gifts to an Earthman. But this is not altruism; it is, rather, a test. "The fate of his race hangs on his reactions to [the gifts]." And one of the aliens mentions that he himself is "a sort of snake." The gifts do not include an apple from the Tree of Knowledge, but they might be just as likely to lead mankind astray. - Summary by Paul Hampton