Bosses
SuperUniques are special boss monsters with preset names and stats. They are usually found in fixed locations and are often part of a quest or other special event. Only a few such monsters have yet been revealed in Diablo III, and they are listed below. Click the names to see their full articles; this page is simply a master directory.
Siegebreaker Assault Beast
"Living siege Engine of Hell". The Siege Breaker is an absolutely massive "miniboss" shown in the WWI 2008 gameplay video. It's apparent that Blizzard is taking the gameplay with even the minor bosses to a whole new level in Diablo III! We don't know if he's a random encounter or not, but this big bad-ass is found in Leoric Highlands.
Thousand Pounder
Inside the forgotten Tombs of the WWI 2008 gameplay video, we got familiar with the Thousand Pounder as he was summoned in to the scene. He's also seen in concept art work, and looks more like an overly powerful monster than an actual type of boss, like a SuperUnique.
Leoric
The Skeleton King returns in Diablo III, and he's up to his old skeleton-summoning tricks. He's found sitting on his throne, must be awakened by the use of a quest item, and does not return in a good mood. Leoric wields a gigantic hammer and commands a vast army of the undead. He is a quest boss and was the final creature to defeat in the Blizzcon demo build (October 2008.) See The Skeleton King quest article for more details.