He's part siren and wears an amulet to appear as completely human.
He's apart of the rubberfishes crew.
Also since most sirens are born female, he's trans ftm! Him and Sunny are the only trans crew members.
If anyone wants hear more about him I have a post where I talked about him or you can listen to me ramble lol. I'm only slightly embarrassed of my own ideas and head canons haha.
im currently rewriting the Shopkeeper and while doing so i decided to read the wiki to catch up on lore and how to make it make sense. who the fuck was going to tell me i completely skipped over green gregory and my main idea for the Shopkeeper is almost exactly the same as him what the fuck man