Dungeons & Dragons - Icons of the Realms Set 11 Waterdeep Mad Mage BoosterPortal, named after the gaping pit in its common room. At the bottom of this crumbling shaft is a labyrinthine dungeon known as Undermountain, domain of the mad wizard Halaster Blackcloak who has seeded his lair with monsters, traps, and mysteries. This set of collectible figures perfectly represents many of the monsters and villains found throughout the 23 levels of Undermountain detailed in Waterdeep: Dungeon of the Mad Mage. Waterdeep: Dungeon of