The Spider Gown is a black dress with a long skirt and sleeves, and yellow-orange hems and cuffs.
The Spider Gown grants good boosts to Defence and Magic Defence, along with an HP bonus. It can also randomly cast the Demon Mirror summon, which will deal Dark-elemental damage to a single foe and inflict Curse on them. It's overall a decent defensive armor (albeit a bit lacking in terms of special effects), and is also an alternative to the Dark Gown if you want the boost to Dark-elemental skills (particularly because the Spider Gown can be obtained much earlier in the game).
| A spooky dress for Halloween.