The deck starts by casting efficiently-costed creatures with strong secondary abilities including Thornvault Forrager (ramp, squirrel fetch), Osteomancer Adept (deathtouch, reanimate), Valley Rotcaller (menace, drain), Vinereap Mentor (food tokens), Bonecache Overseer (draw)
Tuning frequently takes another form, adding answers to your opponents
Spiders have few viable legendary commanders aside from Ishkanah, Grafwidow and Thantis, the Warweaver, so there's plenty of room for casual Commander players to build a new Spider deck around Shelob to take advantage of its intriguing abilities
Its fairly easy to commit crimes in decks built to do that, and getting 3/3 Zombie Rogue tokens as a result is strong
That said, Abrupt Decay can almost literally always be used against stuff like Lightning Greaves, Rhystic Study, Song of the Dryads or anything else thats bothering you
They just won't be attacking