Wraith mutagen is an alchemy ingredient in The Witcher 3: Wild Hunt.

They are needed to craft the wraith decoction and, like all special mutagens, they can only be dropped by their corresponding creature. They act like lesser green mutagens when placed in the diamond-shaped slots in the character panel.

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.
• Unlike most monster specific mutagens this one is a guaranteed drop and since wraiths are a common enemy there is no real challenge in obtaining this mutagen.