Thanks for sharing these!

I hope there's a second series for the show so that we can learn more about the characters, especially Cook! In addition to what blueswan said, other fans have also speculated that Cook must be strongly connected to the ship because he's always aboard. He hasn't left the ship to join them in their adventures on land.

I don't know what Cook's ethnicity is, but the actor is Filipino. Religion in pre-colonial Philippines involve ancestor worship.