Yup. Svirfneblin were first in the D series (D-2 I believe). They can be a terrific resource for surface dwellers who have to traverse the Underdark. They can provide valuable recon, supplies and places to rest and recover.
The underdark race that Svirfneblin would likely ally with are Gray Dwarves (Deep Dwarves) who are LN as I recall.
What you want are Derro. Derro are chaotic evil underdark 'dwarves' that have been mutated and driven insane by worshipping their freaky, chaotic evil gods. They have 'savants' who are their super-intelligent leader caste.
While they probably wouldn't work closely with Duergar, they could provide a second enemy down there for your PC's.
If you are running an Underdark campaign, I would highly recommend you try to find copies of Drizz't Do'Urden's Guide To The Underdark and The Night Below. DDGTtU is a terrific resource that can be used in any campaign. The Night Below is one of the best mega-adventures I've ever played in. Derro, Kuo-Toans, Aboleth, even a race of good, Underdark Elves. And best of all, not a Drow to be seen. Both products are unfortunately out of print, but perhaps you can get lucky on E-Bay.
The underdark race that Svirfneblin would likely ally with are Gray Dwarves (Deep Dwarves) who are LN as I recall.
What you want are Derro. Derro are chaotic evil underdark 'dwarves' that have been mutated and driven insane by worshipping their freaky, chaotic evil gods. They have 'savants' who are their super-intelligent leader caste.
While they probably wouldn't work closely with Duergar, they could provide a second enemy down there for your PC's.
If you are running an Underdark campaign, I would highly recommend you try to find copies of Drizz't Do'Urden's Guide To The Underdark and The Night Below. DDGTtU is a terrific resource that can be used in any campaign. The Night Below is one of the best mega-adventures I've ever played in. Derro, Kuo-Toans, Aboleth, even a race of good, Underdark Elves. And best of all, not a Drow to be seen. Both products are unfortunately out of print, but perhaps you can get lucky on E-Bay.