picture description: This is one of sixteen balls used to play a human game called pool.  Pool is played on a flat slate table covered with felt.  Humans hit a white ball, called the cue ball, with the end of the a stick, called a pool cue, in a highly stylized manner.  The table has pockets built into the sides and corners.  The object of the game is to cause the cue ball to knock certain balls into the pockets.  The eight-ball is also a symbol of peril, since in one form of pool, called "eight-ball," causing the eight-ball to go into a pocket prior to doing so for all of one's designated balls causes one to lose the game.