Bosses, Baldur's Gate 1

Bosses, Baldur's Gate 1By "boss", I mean a particularly tough Baldur's Gate enemy, or rival adventuring party, that usually must be defeated if we are to progress in the plot, or lay claim to having played Baldur's Gate 1 Original with courage.The difficulty of a given boss encounter varies greatly depending on party composition, level and items. For example:Bee-line the plot-critical path?