Allakhazam.com says that Skoll, a two-headed dog in Iarnvidiur Dungeon, drops remains.

I've tried several times to kill Skoll to see whether this is true, but only managed to do it once. He did not drop remains.

If anybody has seen a Skoll remains, please send me an email.

Many thanks to Shewarrior and Haytr of Gaheris for helping me kill Skoll. And thanks also to the people who wiped with me on four earlier attempts. :)