It has been brought to my attention that the web updates to Monsters of Faerun is absolutely full of added LAs.
In particular, the "hairy spider" was given LA+0.
Stats:
Fine size, vermin type
Poison immunity
-8 STR, +4 dex, -- int (IE: mindless) , -8 cha
Immune to poison
Racial bonuses of +4 to hide, +6 to jump, and +12 to spot.
Can be used as a familiar.
So, for an arena game, an incorporeal undead hairy spider would actually be able to bypass the otherwise-invincible "Mindsight+touchsight+lifesense" sensory combination. The main issue is, well, their stats suck, and mindless is pretty crippling, since you don't get feats or skill points.
How do we make it not suck?
Consensus says: levels in druid, of course. Druids don't care about strength, intelligence, or charisma penalities. And the druid 4 spell from CC, Iconic Manifestation, gives you int 3 for the duration of the spell. Since you aren't mindless, you can choose all those feats that you didn't think you could have. Pick your feats on the fly!