This is easily one of the most unfair decks I have built. Most of my things are private, as for personal use, but this one is so fun and so nasty I've decided to make it public for other's to consider.
100% spiders, so everything you'll control has Reach. That'll control those pesky fliers your opponent's may have.
Turn 2, drop Deadly Recluse. That'll keep opponent's at bay. Turn 3, throw down Bow of Nylea. From here on out, they'll be scared to attack. Your goal is to bide your time. Wait in the darkness, and lunge out when your opponent has their back turned.
Hold onto Acid Web Spider for when your opponent plays any equipment. Make them see how much you disagree with that. True, normal artifacts and enchantments will slip by, but at least there's some sort of control.
Blightwidow + Rogue's Passage is a formidable combination, and if your opponent isn't paying attention it'll sneak up on them real fast.
Whenever your spiders die, go ahead and tap Swarmyard to bring them right back. This works especially great on Penumbra Spider, because he'll die and net you a 2/4 token, then tap for regeneration. So feel free to openly block as often as you want with these little buggers.
Obviously we can't have a Tribal deck without Door of Destinies, so let's pack in 4 and make things truly unfair.
Should your opponent be unfortunate enough to cast something with Flying, or if they're stupid enough to play Archetype of Imagination, you've got Silklash Spider to drag them into the grave.
Watcher in the Web is a great defensive spider, and combined with either Bow of Nylea or Swarmyard, you've got a formidable tank. Combined with both, nothing will want to attack you.
On the side of Bow of Nylea, feel free to tap it for +3 life. It's not much, but it'll add up as your opponent skips combat phases trying to figure out what to do. No, this deck won't survive a well built burn deck, but it's not really supposed to. It's more a intimidation deck, over a survival deck. You don't want your opponent to attack, simply out of fear of losing. Ironically (And appropriately) the way your opponent will have to get around this deck is to "kill it with fire."
Once you have a decent swath of spiders, hone in with Triumph of the Hordes. Everything gets Infect, +1/+1, and Trample. Attack with everything.
When your opponent struggles to declare blockers, strike the final blow with Winds of Qal Sisma. All damage from their creatures is prevented, and if you have Bow of Nylea out like a good bastard, everything will die with just 1 point of damage. Trample kicks in and Infect takes over for an instant kill.
So what happens if you don't have Door of Destinies out? In order for Winds of Qal Sisma to have the Ferocious ability to activate, you need something with Power 4 or greater. The highest here naturally is 3 with Acid Web Spider?
Well, there's Bow of Nylea that can tap for a +1/+1 counter. So you can buff throughout the game with that. Also, remember that Acid Web Spider is a 3/5. Triumph of the Hordes gives everyone +1/+1, so it'll be a 4/6, which matches the requirements for Winds of Qal Sisma.
Lastly, if Casual is more of your style, go ahead and replace Winds of Qal Sisma with Arachnogenesis. Now when your opponent attacks, you can block everything with Deathtouch and prevent all of their damage, while maintaining your own. In addition to this, you'll pack in X 1/2 spider tokens, for more unsettling fun. It also functions quite well in place of Winds of Qal Sisma, because when played on your turn while you won't get the tokens, you'll still prevent all of your opponent's combat damage, giving you the same effect.
In short:
Bow of Nylea + Triumph of the Hordes + Winds of Qal Sisma or Arachnogenesis = so much Poison you'll think your opponent is a member of an 80's glam band.
