The bear (곰, gom) carries more symbolic weight in Korea than almost any other animal on this list, because of its direct role in Korea's founding myth: in the legend of Dangun, a bear (Ungnyeo) endures 100 days eating only mugwort and garlic in a cave, in exchange for the chance to become human — and succeeds, later becoming the mother of Dangun, Korea's legendary first king.
That myth shapes the whole reading: a bear dream is generally about patient endurance through a difficult, isolating transformation in order to become something greater on the other side — not a quick fortune, but a hard-won one.
A bear that seems large or intimidating but doesn't actually attack is read as a challenge that looks more frightening than it turns out to be, similar in spirit to some of the more manageable animal-threat dreams elsewhere in this category. Encountering a bear specifically inside a cave draws the myth in even more directly — read as a period of necessary isolation or hardship that precedes a real breakthrough, exactly like the bear's hundred days in the story.
A bear being aggressive and genuinely dangerous, rather than merely present, shifts the reading toward a real obstacle requiring serious effort or patience to get through — the myth's difficulty without yet its guaranteed reward.