What made the Mares of Diomedes particularly dangerous?

The Mares of Diomedes were particularly dangerous because they were known to eat humans. This characteristic made them particularly fearsome, as they were not just any ordinary horses, but man-eating beasts that were ferocious and aggressive. According to myth, Diomedes, the king of Thrace, fed them human flesh, which contributed to their brutal nature.

The other options do not accurately represent the nature of the Mares of Diomedes. While fire-breathing horses and flying abilities are common in various mythologies, they are not attributes associated with these specific mares. Additionally, their speed, although impressive, is not the defining factor that made them notorious; it was their predilection for human flesh that set them apart as a true threat in the stories of Hercules’ Labors, where he was tasked with capturing them.