Deathbone Guardian

Deathbone Guardian is the plate Scholomance instance set.

Source
Each piece can be dropped by the six Bosses before Darkmaster Gandling in Scholomance:


 * Lord Alexei Barov
 * Doctor Theolen Krastinov
 * The Ravenian
 * Instructor Malicia
 * Lady Illucia Barov
 * Lorekeeper Polkelt