I am one of those people that believe Kaido is actually a dragon that ate the Hito Hito No Mi, Model: Oni (or something similar). That would probably mean his son Yamato is a dragon.
![](https://www.opfanpage.com/wp-content/uploads/2020/05/maxresdefault-17-1024x576.jpg)
This then would explain a few things:
1.The reason why Yamato is difficult to catch (needing to send all the Flying Six).
![](https://www.opfanpage.com/wp-content/uploads/2020/05/94308839_232902911127357_2175699858165641961_n.jpg)
2.It seems quite evident that Kaido and Big Mom are planning a wedding to confirm their alliance.
![](https://www.opfanpage.com/wp-content/uploads/2020/05/w99ayrut01y41.jpg)
3.It’d make sense that Big Mom would deeply want Yamato in her family if he’s a dragon, since he would most likely be on eof the three races she’s missing (the other two being giants and whatever King is).
![](https://www.opfanpage.com/wp-content/uploads/2020/05/EBBE3p_WwAEjvZH.jpg)
4.Marrying Yamato to one of her daugthers could be the big debt that Kaido was mentioned to owe to Big Mom.
![](https://www.opfanpage.com/wp-content/uploads/2020/05/bomggkx8ccp31.png)
*Theory by Ismoista