Here are the four strongest ancient giants or their descendants revealed throughout the entire One Piece series.
4. Little Oars Jr.

Little Oars Jr. is a descendant of Oars and one of the largest giants in the entire series. He serves as the captain of the Little Pirates crew and is also a member of Whitebeard’s Great Fleet. He first appears during the Marineford arc to help rescue his friend Ace.
Named after the legendary ancient giant Oars, who was known as the physically strongest character in the series, Little Oars Jr. shares a similar appearance with his ancestor, featuring large horns and immense size that dwarfs other giants.
3. Oars

Few historical figures in One Piece inspire as much fear as the ancient giant Oars. Born 500 years before the story begins, he was known as the “Continental Puller” due to his massive size and overwhelming strength, suggesting he could drag entire continents and islands across the sea. At his peak, he ruled over many islands.
Oars ultimately died on a mysterious island known only as the Ice Island. His body was preserved in ice, which led Gecko Moria to use it for his plans during the Thriller Bark arc. Despite his power, the resurrected Oars was eventually defeated by Nightmare Luffy.
2. Loki

While not an ancient giant like Oars or Little Oars Jr., Loki is a descendant of the giant race and the prince of Elbaf. Though smaller than the other two, Loki’s strength is considered legendary. He was known for causing many disasters at sea until Shanks defeated him and sent him back home.
Loki’s true power comes from a mysterious Devil Fruit he consumed. Though details about this fruit remain unknown, it is said to be a legendary treasure of Elbaf that allows the user to transform into the Sun God Nika from mythology. Owning this Devil Fruit has made Loki one of the strongest characters in the series, and fans eagerly await seeing its full power.
1. Harald

Like his son Loki, Harald is a descendant of the ancient giants and one of the strongest figures in One Piece history. A single conversation about his first encounter with Rocks D. Xebec confirms that Harald possessed advanced Conqueror’s Haki, matching the power of Rocks, who was considered the strongest person of that era.
This is no surprise since Harald has always been regarded as the strongest warrior on Elbaf. Although he sought peace with neighboring countries and despised Elbaf’s warlike legacy, his strength was proven to rival Pirate King Roger, Rocks, Whitebeard, and Garp at their peaks, all among the most powerful characters in One Piece.