You will get the secret location of the grave hag mutagen and trophy in the Witcher 3: Wild Hunt. This mutagen is used to brew the Grave Hag decoction which accelerates vitality generation for each foe slain in battle. The trophy gives 5 percent bonus XP against humans and nonhumans when equipped on Roach. The grave hag is near Lindenvale, Velen and you get the quest from the notice board and grave digger in that town. This sets up an epic boss fight in the grave yard with Mourntart. The quest is the level 10 Contract: Merry Widow. Additional music by www.BenSound.com Game play from The Witcher 3: Wild Hunt Complete Edition by CD Projekt Red. (c) 2020, Linus Wilson, Vermilion Advisory Services, LLC www.SwordsTV.com