Saw this pirate spider (family Mimetidae, Mimetus or Reo) on the side of my building while returning home the other night and quickly ran inside to grab the camera. They specialize in eating other spiders, particular orb-weavers. I hope this one eats its fill of Zygiella around my lights and has a billion babies, because they are really cool-looking.
The family Mimetidae, commonly called pirate spiders, are spiders which typically feed on other spiders.