... I wanted to bound, to float in my madness through eldritch depths of unhallowed black blood. I wanted to cling to the writhing breasts of Yibb-Tstll. Insane....
~ Brian Lumley , -Rising with Surtsey

Yibb-Tstll (The Patient One) is an obscure god, said to watch at the center of all time as the universe revolves. Because of this insight, only Yog-Sothoth is said to be wiser. Its blood, the Black, is a weapon which takes the form of black snowflakes that stick to and smother a victim. The god's touch causes an instant change in the person affected—this change is usually fatal but occasionally brings some benefit.

Yibb-Tstll is sometimes described as an immobile, dark, tentacled entity with a pulpy, alien head, detached eyes, and large bat wings under which countless Nightgaunt suck black milk from its innumerable breasts.


Yibb-Tstll makes its major appearance in The Horror at Oakdeene. Yibb-Tstll also appears in The Caller of the Black.

Having a close connection to the Great Old One Bugg-Shash,[1] so should Yibb-Tstll be regarded as a Great Old One - specifically in the Drowners group introduced by Brian Lumley, parasitic alien entities which thrive by vampyrizing the Great Old Ones themselves[2] - though in RPG materials she is classed as "Outer God".[3]




  1. Aniolowski's, Malleus Monstrorum, p. 131. ISBN 9781568821795
  2. Harms', Encyclopaedia Cthulhiana, p. 324. ISBN 9781568821696
  3. Aniolowski's, Malleus Monstrorum, p. 241. ISBN 9781568821795