That is what I think too. Remember, he is known as "The Strongest Creature". Oda sensei used the word creature rather than a human when emphasizing on Kaidou. At first I thought that as an over-exaggeration of a 'word' to describe just how strong Kaidou is gonna be. But we have also seen that Big Mom used the 'relatively' similar term when mentioning about Kaidou. I guess that was during a small skirmish between Luffy Vs Big Mom encounter where Big Mom mentioned Kaidou as a 'thing'.I was gonna make that thread yesterday but dropped it. We've seen a human fruit but only one model while we've seen multiple models of other animals so why not people? Could Kaidou be a Dragon who has eaten a human fruit model giant?
Shuntenmaru is Ashura Doji and was one of the silhouettes of the three they were looking for
So I held my doubts since then!. Go ahead with your thread. Will be good to read your thoughts.