Kaido of the Beasts is the captain of the Beasts Pirates and one of the Yonko.
As one of the Yonko, Kaido is among the strongest pirates alive, renowned as the “Strongest Creature in the World”. He attempted to take Whitebeard’s life, something few would dare, and subsequently clashed with Shanks. When Gekko Moria was in his prime, Kaido fought him and emerged victorious, having killed his entire crew. In Wano, Kaido defeated Luffy with just one hit!
The greatest sign of his strength is his apparent inability to die due to his tremendous toughness and durability. He has been caught and tortured 18 times, and people as powerful as the Marines and other Yonko have attempted to execute him 40 times only to fail as Kaido survived every single attempt because every single execution weapon broke when being used on him. Most notably, Kaido has jumped from 10,000 meters from the sky onto the ground, creating a massive shockwave strong enough to sink a large ship nearby, and emerged only with a headache; it has even become a hobby for him to attempt suicide, only for it to fail.