Desecrated Leggings

Desecrated Leggings is a tier 3 armor token. It can be exchanged along with various items at various NPCs at Light's Hope Chapel for the following items:
 * Leggings of Faith
 * Frostfire Leggings
 * Plagueheart Leggings

Source
This item dropped from Loatheb in the original version of Naxxramas.