Grave hag mutagen is an alchemy ingredient in The Witcher 3: Wild Hunt and is used to craft grave hag decoction. They act like lesser green mutagens when placed in the diamond-shaped slots in the character panel.
Like all special mutagens they can only be dropped by their corresponding monster. Grave hags in the wild are quite rare and high level, so the earliest and most reliable way to obtain this mutagen is by completing Contract: The Merry Widow, during which Mourntart is guaranteed to drop it.
Notes[]
- In an undocumented change for Patch 1.08, all mutagen icons were changed. However, there was still a bug for those on Steam and Origin that didn't reflect this and was later fixed in Patch 1.22. Despite this, some may still see the original icons instead, even with a fully patched game.