The Drunken Lizard Pub

Does anyone know where the bloody heck I find this. I'd like to make a detox potion or 3 but I've nary seen Serpent Venom at vendor nor drop. I've currently got the eye fungus and thanks to an itchy F2 finger didn't have a save to revert to.

Eye fungus is a disease, it's not poison - a Detox potion won't help you there. You can buy cure disease potions (the cheapest will do) easily, or you could talk to a priest.

Doh, I should learn to read my own bloody handwriting. I actually have the items for a cure potion. I'd still like to make a detox which does require serpent venom so question is still on the table.

Random loot in chests or merchants. Have to go back every few days to check the new items in stock.