There are many merchants in Sekiro: Shadows Die Twice. These NPCs will buy useless items from you or sell various consumables like Pellets or Antidotes. Below you can check the location of Toxic Memorial Mob and what you can buy from this merchant.
How to find Toxic Memorial Mob?
Toxic Memorial Mo bis in the bottom section of Sunken Valley. This area is located behind the Gun Fort - you unlock it after defeating Genichiro Ashina, the main boss in Ashina Castle. Kuro will give you the key to the gate behind the fort. Reach Riven Cave Sculptor's Idol - the merchant will be right below you, at the very bottom of the Valley. To get there, you have to jump down and use the grappling hook on statues and trees. Watch out, the ground at the bottom of the Valley is poisonous!
What can you buy from Toxic Memorial Mob?
- Green Mossy Gourd - a special item; an antidote that reduces poison, refills after resting; after getting it, you can ignore Antidote Powder.
Dragon's Blood Dropplet
Green Mossy Gourd
Heavy Coin Purse