Think of a dragon tomb. Replace the dragon with a bunch of a certain type of mob but have a large amount of that mob in the tomb. If you and some friends win, instead of getting a dragon egg, you get a mob head. The mob head can be redeemed for perks or can be used for head gear. SHORTENED VERSION.
I gave up trying to understand in half of the paragraph... EDIT: Shortened version answer; It seems cool like the idea.
Sorry but the staff is nearly done with the dragon tomb update, I doubt they will scrap it at the last minute to recode it for this, but it was a fair suggestion.
Thanks for the translation, SouthPark. I didn't interpret it as something that would replace Dragon Tombs, but as an additional type of dungeon. Seems like it would be relatively easy once Dragon Tombs are done for Aikar to use it as a template for other dungeons.