No, he’s not a Giant, Lunarian or a Buccaneer and no he’s not Shank’s mother’s ancestor.
I think that Joy Boy is the forefather of the Monkey D Family but Monkey D is a name that starts with Garp who I think is Joy Boy’s son sent to the future using Toki’s power as an infant to protect him.
Therefore he’s Dragon’s grandfather and Luffy’s great grandfather.
The reason why I think that is simply if we look at all the key figures in the story related to someone from the void century is their descendant.
Shirahoshi is the descendant of the original Poseidon, Vivi is Lili’s descendant, Zoro is Ryuma’s descendant, Blackbeard is Davey Jone’s descendant and Loki is the descendant of the God of war. So it stands with reason that the modern Joy Boy is the descendant of the original Joy Boy.
I think that Joy Boy is the forefather of the Monkey D Family but Monkey D is a name that starts with Garp who I think is Joy Boy’s son sent to the future using Toki’s power as an infant to protect him.
Therefore he’s Dragon’s grandfather and Luffy’s great grandfather.
The reason why I think that is simply if we look at all the key figures in the story related to someone from the void century is their descendant.
Shirahoshi is the descendant of the original Poseidon, Vivi is Lili’s descendant, Zoro is Ryuma’s descendant, Blackbeard is Davey Jone’s descendant and Loki is the descendant of the God of war. So it stands with reason that the modern Joy Boy is the descendant of the original Joy Boy.