According to Queen, King enjoys torturing people and is known to get pleasure out of it. He is shown to be disrespectful to his fellow calamities Jack and Queen when talking to them and like Queen resorts to insults and name-calling. King is also shown to be loyal to the Beasts Pirates and is willing to go out of his way to take down Big Mom's ship with her strong fighters despite their powers.
As one of Kaido's commanders, he is very strong and is implied that he is stronger than Jack who is quite strong himself.
Devil Fruit Abilities
Ryu-Ryu no Mi, Model: Pteranodon
King ate the Ryu-Ryu no Mi, Model: Pteranodon, which allows him to become a Pteranodon hybrid or full Pteranodon at will. It also gives him the ability to fly and perform powerful aerial attacks, as seen when he was able to knock down the Queen Mama Chanter and throw Big Mom in the sea.
In the past, King along with Queen, Jack, and their leader Kaido assisted Kurozumi Orochi in his plot to take down the Kozuki Family 20 years ago in a coup. While doing so, King assisted Kaido and Orochi in destroying the Kozuki Family's palace and killing the Kozuki Family. Since Orochi's takeover of the country, King along with the Beast Pirates took up residence in Wano Country and maintained their allegiance to Orochi's men.
King appears with Queen and Jack at Onigashima Island where they discussed the new business partners the Beasts Pirates can ally with since Doflamingo was no longer a business partner to the Beasts Pirates. Soon, King and Queen began exchanging insults and then they both turned to insult Jack. Moments, later King appears when he gets news that Big Mom and the Big Mom Pirates are trying to enter the country. He snaps the ropes that linked their ship to the carps which helped them get up the waterfall causing the ship to fall and Big Mom to fall into the ocean. King receives praise from his comrades for the stopping the Big Mom Pirates.
King appears in Onigashima along with Queen and Jack to watch a chained up Big Mom eat food. King remarks that he made her fall off the waterfall, but Queen blames him for enabling her to enter the country. Big Mom tells King that she is willing to forgive him for his actions and tells him that he is a part of one of three races of people that is not a part of her country. Big Mom says that King is a part of race of people who was allegedly wiped out from history. King refused her offer. King witness Kaido ordering the Beasts Pirates to unchain Big Mom and witness the clash between both emperors. When the fighting with Kaido and Big Mom ended, King tells Queen that the Numbers are coming to the upcoming banquet to which Queen remarks about how he does not like them since they drink alcohol a lot. Afterwards when Queen wonders why Kaido and Big Mom are so happy, the two emperors announced that they are now allies and their pirate teams have joined forces in order to take over the world. They said that after their alliance, both emperors will go back to fighting one another.