Bosses in Diablo 2 covers a compendium of these various special type of Enemies that a player can encounter in the game. Bosses have a higher amount of health and are distinctively unique with their own set of moves. Bosses match the description to Super Unique Monsters but each Boss plays the role of the final enemy for each act, and it is required to defeating a Boss will give the player access to the next Act.
You can find detailed information about the Bosses in Diablo 2 and how to defeat them on their individual page.
All Bosses in Diablo 2
Each Act Boss plays the role of the final enemy for each act, and it is required to defeating a Boss will give the player access to the next Act.
By defeating Mephisto, Diablo and Baal in Hell Difficulty, these boses will drop special keys. These keys can open portals to access the Pandemonium Event locations. In these locations, the player may encounter the "Uber" versions of all the Bosses which are the same Bosses with buffed stats, and the player may have to fight them one after another.
Pandemonium Event Bosses