Non-evil Underdark denizens

[Shin Okada]

My current campaign is using 3.5e rule, but information from other edition books may help if it can applicable to 3.5e default (Greyhawk) world.

Now some considerable amount of Underdark monsters are in alliance and invading surface world, with the help of an Empire in the Plane of Shadow which has a way to obscure sunlight in vast area. I already used Drows, Duergars, Orogs, Kuo-Toas and some other aberrations.

Now I want to let appear some traitors, defectors or oppositions amongst some underdark races. A member of such a group is working as a spy in the invading army and will be found and caught, then happened to be found by PCs and leads the heroes into some adventures in the underdark.

Drows following Eilistraee came to mind easily. But they are old hat. Svirfneblin may work but they too are already used often.

Do you have any other interesting idea?

 

[Dandu]

Earth Elementals
Mind Flayers
Formians

 

[Shin Okada]

Earth Elementals
Mind Flayers
Formians

While interesting, I wonder if PCs will co-operate with Mind Flayers. The conflict between Thoon Mind Flayers and usual Mind Flayers can be interesting, though.

I have never thought of Earth Elementals. Possibly, related races can be usable, too. Say, Earth Genasi or Half-Elementals?

I have never thought of Formian either. But now I remember seeing some roaming underground area in Neverwinter Nights computer games. A myrmarch, maybe?

 

[Imaculata]

Any Drow who wishes to overthrow the current Matron.

 

[Mecheon]

Myconids are the other classic neutral race. Of course their issue is they're very, very neutral and most Underdark races would be clever enough to not bother them.

The Formorians and their Cyclops servants could always be a thing, of course they're less 'good' as they are 'the lesser evil' in this case. On the other hand they most certainly dislike elves of all kinds

 

[GreenTengu]

Goblin and Kobolds, of course.

Granted, the Underdark version of anything is going to be more evil than the regular version of it simply thematically. But once you assert yourself as the boss, goblin and kobolds are perfectly content to have whatever alignment you tell them to have... so long as it remains in their best interest.

If they are invading the surface, don't forget that some unlikely surface allies can arise who might be pretty good at fighting the hordes back as well. Orcs, Hobgoblins, Lizardfolk, Giants, Ogre Magi.... I can't imagine any of them would be particularly happy about having their homes invaded by armies of Drow, Mindflayers, Kuo-Toa and the like. They might well be willing to ally with traditional enemies in order to drive them back.

 

[Imaculata]

Duergar, Beholders and Mindflayers are also a good choice. But any alliance with a Mindflayer would probably be temporary, as it would turn on them the moment they are no longer needed.