Hallowed Be Thy Name

I wouldn't be so fast to pin it to an Iron Maiden song. Ever hear of the Lord's Prayer? "Our Father, who art in heaven, hallowed be Thy name. Thy Kingdom come, etc."

Iron Maiden is "more known" than the Lord's Prayer? You're kidding, right?

Tigole has posted the following regarding this achievement

We removed the mask achievement from the "Hallowed Be The Name" meta-achievement
This will go live in 3.0.3 and will most likely happen during the event.

If you happen to fulfill all of the criteria with the exception of the 20 mask criteria before that patch goes live the achievement will stay incomplete until the day patch 3.0.3 goes live. As soon as the patch goes live, you'll have the achievement as well as the title.

Source: http://forums.worldofwarcraft.com/thread.html?topicId=11296671390&pageNo=1&sid=1#3