One of the notable things about Kaido is that people didn't consider him human. Hence, the "World's Strongest Creature" title.
He seems to belong to some race of people called "Onis". They look like ancient giants, but are much smaller.
One of the most notable things about people with ancient giant blood is their horns, which Harald himself took off.
Could the horns indicate that Onis are a mixture of ancient giants and humans, like Buccaneers are a mixture of giants and humans?
Worth nothing that Kaido is just slightly taller than Kuma, meaning he fits the physical range of a "hybrid".
He seems to belong to some race of people called "Onis". They look like ancient giants, but are much smaller.
One of the most notable things about people with ancient giant blood is their horns, which Harald himself took off.
Could the horns indicate that Onis are a mixture of ancient giants and humans, like Buccaneers are a mixture of giants and humans?
Worth nothing that Kaido is just slightly taller than Kuma, meaning he fits the physical range of a "hybrid".