Don’t blink.

1.  First fact: this list will most likely be out of date after this Saturday night, when the Angels return to Doctor Who.  (Cannot wait.)

2.  Also known as the Lonely Assassins, they were created by Steven Moffat in the classic “Blink” episode (part of the Doctor 10 and Martha year of the show).

3.  The Weeping Angels don’t really kill a person; instead, if one touches a person, it sends him/her back in time so that it can feed on the energy that is released by this time transfer.

4.  The Weeping Angels look like angel statues found in cemeteries (usually with their hands covering their faces), hence their name; but they are in fact living creatures who become frozen and stonelike whenever another creature is looking at them.  (Weeping Angels cocktail parties are notoriously boring.)

5.  When no one is looking, however, they can be enormously fast – which is why one is advised to not even blink when in their presence.  (Alternate eye winking is allowed, however.)

6.  It’s not clear whether all Weeping Angels resemble angel statues or if perhaps any statue could in fact be revealed as a Weeping Angel, even if it did not have an angel appearance.  (Rumors surrounding this Saturday’s episode suggest that the Statue of Liberty itself might be a Weeping Angel.)

7.  Not even the Doctor knows where the Weeping Angels come from, although he says they are almost as old as the universe.  (And some of them look it.)

8.  In a 2012 poll, the Weeping Angels were declared the best of the Doctor Who monsters, earning close to 50% of the vote.  (The Daleks, who have often topped such polls in the past, came in second with 17%.)

9.  In a short (3 minute) 2009 webisode on the Doctor Who Adventure Calendar website, Captain Jack relates the story of Julia Hardwick, who was sent back in time by an Angel encounter and, it is suggested, became her own ancestor.  (Wibbly wobbly timey wimey stuff.)

10.  “Blink,” the Doctor Who episode that introduced the Angels, was awarded the Hugo Award for Best Dramatic Presentation (Short Form) in 2008.