The Diablo 2 Wiki
The Diablo 2 Wiki archive is available for anyone looking for information on Diablo 2. All information here is pre-D2R but contains a lot of useful information that is still relevant. Updated sections for new D2R features can be found on the PureDiablo Diablo 2 section

Category:D1 SuperUniques

Category page

This category lists all of the SuperUnique (boss) monsters found in Diablo and Hellfire. All of the bosses in Diablo and Hellfire are SuperUniques; there are no random bosses with random modifiers, as are found in Diablo II.

There are multiple types of SuperUniques for all base monsters in Diablo; they are all tied to a certain level, and will be found in any game when their base type of monster spawns on that level. There are also three special monster type SuperUniques in Diablo: The Butcher, The Skeleton King, and Diablo, and three more (the only bosses found in that game) in Hellfire: Na-Krul, The Defiler, and The Hork Demon.

See the SuperUniques page for more general information about bosses in Diablo and Hellfire. See the individual monster pages for their full stats.