Shadowstar

Vendor

Not sold by a standard vendor.

Crafting

Not craftable.

Gathering

Not a gathered material.

Dropped by

Draugorc Brawler	level 52
Forbidden Book	level 52
Shelfwarden	level 52
Guargantuar	level 52
Mimic Guardian	level 52
Scorching Writ	level 52
Researcher's Familiar	level 52
Hound of Kyrios Ghast	level 52
Crimson Assassin	level 52
Crimson Murderess	level 52
Wrathful Researcher	level 52
Wrathful Researcher	level 52
Delphinad Mercenary	level 52
Delphinad Mercenary	level 52
Crimson Assassin	level 52

and 23 more.

Note: the monster level tells you the zone tier where it is found; exact spawn coordinates are not published in the game data. See the World Atlas for zone level bands and Dungeons & Raids for instanced drops.