The figures are a combination of toy spiders and plastic spider-shaped jewelry sold as party favors. I picked them up last year on sale the day after Halloween. The bases are cut from cardboard and painted and flocked normally. These minis can freak out arachnaphobes--I even had one player who saw this army and said he would never play against it because he can't stand spiders!
The main component of this army is 12 elements of Hordes on 60mm x 60mm bases.
The big spiders were various colors of plastic; I drybrushed them to bring out the details. The smaller spiders came in black or bright green plastic; I spray-painted them black and then drybrushed in idfferent hues.
I also used three of the big spiders as Sneakers elements. They're on 60mm x 40mm bases. These guys always underperform and usually just die too easily, counting 9 AP against my army total--and unlike Hordes or Lurkers, I can't bring these fellas back.
In addition, I placed three of the small spiders on 60x40 bases to serve as Lurkers elements. I always seem to get great mileage out of this element type. These particular critters, acting in combo, actually brought down a Behemoth in one game.
I also have a Stronghold, which consists of a plastic tree and the top of the container for the big spiders. It's encased in webs and swarming with the smaller arachnids.
Like I said, this army disappoints on the battlefield. With 12 Hordes, 3 Lurkers, and 3 Sneakers, it's not particularly combat effective--and once the Sneakers all die, it's a quick three points to losing half the army. Still, it makes for a challenging game.
Happy Halloween!