I decided to make a Poke-pirate Captain based on Mario's main nemesis Bowser the Koopa King.
Pirate is not exactly the first thing you typically associate with Bowser since he's typically surrounded by Lava, but if we don't take Pirate to be the traditional "Sea Pirate then Bowser has a lot of Pirate traits, and also straight up just does actual Pirate things:

First off, he has a fleet of literal Flying Pirate Ships that have a Jolly Roger that features his own face on them, and he tends to use these ships on pillaging attacks typically the Mushroom Kingdom and takes whatever he wants, which is typically Princess Peach but he has been known to steal other things too and as Jack Sparrow himself says: "Not all Treasure is Silver and Gold mate."

Secondly, he has a very diverse crew of underlings who all seem to respect and speak highly of him, Which could be seen in Pirate crews; They tended to also be diverse made up of people from many backgrounds who were typically outcasted from other groups, and the captain stayed a captain by benefiting the crew members and being a magnanimous leader.

Bowser also just kinda has that Rock'n Roll Punk rebel against the system vibe, I know a vibe is not solid evidence but I feel like it's important for being a Pirate to have style...so while he's not usually out at sea I think he counts for this sake as being some type of Pirate.

I came up with the name Geobukseon from the Korean Turtle Ship, the first Ironclad Warship reinforcing it's hull with Metal Plates that made them a Tank in Naval battles during a time when all other Ships were still made of wood. The Admiral who came up with these won several major battles against the invasion of Japan. Also The name “Koopa” from a Korean Rice Soup dish called Gukbap. So I was thinking a Korean Heavy Armored Turtle Boat becoming a Korean named Heavily armored Turtle Monster just makes a lot of sense.