Tulzscha

Tulzscha (nickname: the Green Flame) is a fictional character, one of the Outer Gods from the pantheon of H. P. Lovecraft's Cthulhu Mythos. One of the dancers in the court of Azathoth, he appears to humans as a pillar of sick greenish flame; however, there is no warmth in him.

"A belching column of sick greenish flame... spouting volcanically from depths profound and inconceivable, casting no shadows as healthy flame should, and coating the nitrous stone with a nasty, venomous verdigris. For in all that seething combustion no warmth lay, but only the clamminess of death and corruption." -- H.P. Lovecraft, The Festival

Only a few pockets of cultists worship this obscure entity.