6th quest in a seven turn-in quest chain, to obtain [item=188808].
All quests can be picked up from [npc=180950] in Haven, after completing the first chapter of the Campaign in Zereth Mortis.
[npc=180950] /way 34.34 65.89
Once a quest is completed you'll have to wait for the daily reset to get the next quest in the chain.
Day 1 The Burrowed Bufonid - Collect 15x [item=190852] from any Vespoid creature in Zereth Mortis. /way 52.6 43.4
Day 2 The Burrowed Bufonid - Deliver 30x Tenebrous Ribs. Drops from Beast creatures or can be bought on the Auction House.
Day 3 The Burrowed Bufonid - Deliver 200x Shrouded Cloth. Drops from Humanoids or can be bought on the Auction House.
Day 4 The Burrowed Bufonid - Deliver 10x Elysian Thade. From fishing in Shadowlands or can be bought on the Auction House.
Day 5 The Burrowed Bufonid - Deliver 5x Protoflesh. Drops from protobeasts in Zereth Mortis or can be bought on the Auction House.
Day 6 The Burrowed Bufonid - Deliver 5x [item=190880]. Sold by [npc=185748]. /way 58.55 49.80
Day 7 The Burrowed Bufonid - Deliver 1x [item=187171]. Sold by Fruit Vendor just inside the instanced [zone=13577] to your left, before any trash pack.
After completing all 7 quests, you'll be offered The Patient Bufonid which rewards [item=188808].
You do NOT have to do the 7 quests in 7 days in a row. You can do 1, then wait however many days you want, and then do the next.
Video Guide: https://www.youtube.com/watch?v=d3kXs9YTsjc