Landsoul's Horned Greathelm

Other Info
Some have rumored that this helmet is a tribute to Landsoul of the guild, on Alterac Mountains, in recognition of his efforts on the DPS warrior spreadsheet found on Elitist Jerks. However, no blue posts have ever confirmed this to be the case- and in the absence of such authoratative validation many argue that these rumors were started and spread by this particular individual himself.

Source
This item drops from the Blood Prince Council in the 25-man version of Icecrown Citadel.