Fhtagn nagh Yog-Sothoth is the only demo album made by the funeral doom pioneers Thergothon.

It originally was released in November 1991.

[2] The demo was reissued again by Eibon in late 2005 or early 2006.

This demo was released on Vinyl in 2006 by Painiac Records, with new artwork and a bonus track titled "Dancing in the Realm of Shades" from an unreleased rehearsal.

The American funeral doom band Evoken take their name from the second track of this demo.