From Diablo Wiki
Quest bosses are superuniques (and sometimes act bosses) who must be defeated to finish quests and advance through the game. It can be any significance of a boss, such as the Butcher from Diablo I or Diablo himself. Only one is known so far (King Leoric), but more will be added as they are revealed by the Diablo 3 development team.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 skeletal undead. He is a quest boss and was the final creature to defeat in the BlizzCon 2008 demo build. See The Skeleton King quest article for more details.
|Monsters of Diablo III Beasts Beasts: Superunique Demons Demons: Superunique Humans Humans: Superunique Undead Undead: Superunique Objects Bosses Boss Mods Monster Info Fanmade|
Bat - Beast - Blood Hawk - Demonic Hellflyer - Electric Eel - Khazra - Lacuni - Lamprey - Quill Fiend - Rockworm - Sand Monster - Sand Shark - Sand Wasp - Scavenger - Spider - Spiderling - Swarm - Withermoth - Wood Wraith -
|Primary Quest Uniques||
Act One Bosses:
Skeleton King -
The Warden -
Strong CC (Limit 1): Knockback -- Nightmarish -- Vortex -- Jailer
|Act One Uniques||Araneae - Web Spit||Leoric - Summon Skeleton, Teleport Strike, Triple Cleave||The Butcher - Smash, Grappling Hook, Spear, Frenzy Charge|
|Act Two Uniques||Maghda - Forcefield, Summoning Ritual, Punish, Moth Dust, Teleport.||Zoltan Kulle - Fiery Boulder, Time Bubble, Ceiling Collapse, Energy Twister,Vanish, Creepy Laugh||Belial - Phase One: Triple Fireball, Summon Vipers. Phase Two: Poison Meteors, Ground Pound, Lightning Strike, Lightning Breath.|
|Act Three Uniques||Ghom - Acid Slime, Sneeze, Gas Cloud, Chomp.||Siegebreaker - Triple Hit, Charge, Leg Stomp, Grab and Throw.||Cydaea - Pain Bolts, Web Trap, Spider Pits.||Azmodan - Bellyflop, Laser Attack, Falling Corpses, Demon Gate, Pool of Destruction, Globe of Annihilation.|
|Act Four Uniques||Rakanoth - Cleave, Teleport Strike, Blade Strike, Volley, Summon Minion.||Izual - Frost Nova, Frozen, Summon Minions.|| Diablo - Phase One: Claw Rip, Charge, Hell Spikes, Shadow Vanish Grab, Curse of Destruction, Ring of Fire, Ground Stomp, Curse of Anguish, Curse of Hatred. |
Phase Two: Shadow Clone. Phase Three: Overdrive, Lightning Breath.