Lactate of Great Mother Vore.

The Dakomyd. Gary Chalk, The Kingdoms of Terror.

Yes, it does sound a bit death metal, doesn't it?

No mechanics. System agnostic. Fit to your system/setting. Black Milk and Black Ichor have canon status elsewhere, but don't you worry about that.

Odds/evens, Great Mother Vore is a physical entity you can encounter/ a symbolic phenomenon.

Odds/evens, the Lactate is only effective from the source (breaking down if exposed to the air/taken away)/ can be stored and distributed.

Roll d6:

1. Black Milk: a powerful mutagen - blessing to some, corruption to others.
2. Black Ichor: as you undertake your dismal delves thereafter, you are compelled to whisper thanks and imprecations to the Mother.
3. Yellow Acid: lethal poison - save or die; permanent damage even if save made; burns through flesh and metal, bone and stone somewhat resistant; considered Holy Water.
4. Amber Oil: soporific, stupefying, highly volatile, highly flammable, addictive.
5. Ghostmilk: local term for ectoplasm; reacts to magical, psychic and powerful emotional stimuli; capable of possession and being possessed.
6. Lactate Incarnadine: like no other high you have ever experienced; supercharges aura, body and mind; ultimately destroys mortal vessels - they were not made to contain it.