Wraith Spider, Gargantuan (CR 9)

Gargantuan Undead
Alignment: Always chaotic evil
Initiative: +2 (Dex); Senses: tremorsense, darkvision 60 ft., Listen +9, and Spot +8

AC: 17 (-4 size, +2 Dex, +9 natural), touch 8, flat-footed 15
Hit Dice: 24d12+3 (159 hp)
Fort +8, Ref +10, Will +14
Speed: 30 ft., climb 20 ft.
Space: 20 ft./10 ft.
Base Attack +12; Grapple +20
Attack: Bite +15 melee
Full Attack: Bite +15 melee
Damage: Bite 2d8+10 plus energy drain
Special Attacks/Actions: Energy drain
Abilities: Str 25, Dex 15, Con -, Int 2, Wis 10, Cha 1
Special Qualities: undead traits
Feats: Alertness; Cleave; Power Attack; Toughness
Skills: Listen +9 and Spot +8
Advancement: 25-47 HD (Gargantuan)
Climate/Terrain: Any underground
Organization: Solitary
Treasure/Possessions: None

Source: City of the Spider Queen

Energy Drain (Su): The bite of a Gargantuan wraith spider bestows two negative levels (DC 25).

Wraith spiders fight much as they did in life, except that they lack spinnerets to produce webs. Their poison glands are also missing, but those have been replaced by negative energy.

Wraith spiders are undead creatures formed from the chitinous husks of monstrous spiders but animated by evil spirits from the realm of Kiaransalee.

A wraith spider appears much like it did in life, except that its eight eyes are hollow sockets through which the empty interior of its shell is dimly visible. A shadowy aura surrounds the creature, congealing to pure blackness around its fangs.