Monstrous Monday: Spider, Unlight

"It was a creature from the Outer Darkness.  Clothed in the shape of a gargantuan spider, but far more fell.  It's exact shape was difficult to make out, save from where darkness gave way to a deeper unlight.  All we could see were it's monstrous eyes. Each one glowed and betrayed great and evil greed or thirst for light and life."

- From the Journals of Larina Nix

The foul and fell creatures known as the Unlight Spiders are not true spiders, but take that form from the deepest fears of mortal kind.  They are in truth shapeless spirits of the voids beyond the blackness of the darkest realms.  Such is their hunger they feed not just on life, but on the light itself.
They crave light as much as they loathe it.

Here they are for Old School Essentials.

Spider, Unlight
10' long spiders of complete pitch-black color.  Hide in dark webs in the deepest, darkest pits they can find. 
AC 4, HD 7** (32hp), Att 1 × bite (3d6 + poison), THAC0 17, MV 90’ (30’) / 180’ (60’) in webs, SV D8 W9 P10 B11 S12 (F8), ML 10, AL Chaos, XP 1210, NA 1 (1d3), TT Ux2
• Growth: Every time the Unlight Spider drains life levels equal to twice their own HD they grow one size category larger. 

HD	hp	XP
7	32	1,210
14	63	6,600
28	126	26,600

• Energy drain: A successfully hit target permanently loses one experience levels (or Hit Dice). This incurs a loss of one Hit Dice of hit points, as well as all other benefits due to the drained levels (e.g. spells, saving throws, etc.). A character’s XP is reduced to the lowest amount for the new level. A person drained of all levels dies and cannot be raised.
• Infravision: 180’
• Loathe the Light: -1 to-hit in lighted conditions (Light spell) and -2 full daylight (Continual Light spell) conditions.
• Mundane damage immunity: Can only be harmed by magical attacks.
• Poison: Causes death in 1 turn (save vs poison).
• Webs: Creatures caught in webs become entangled and unable to move. Breaking free depends on Strength.
<10: Impossible to break free
10-13: 6 rounds
14-17: 5 rounds
18-19: 4 rounds
19-22: 3 rounds
23+ : 2 rounds
The webs can be destroyed by fire in three rounds. All creatures in a flaming web suffer 1d6 points of damage.