Crocodile, also known as Sir Crocodile and formerly by his Baroque Works codename Mr. 0, is a major antagonist turned influential figure in the world. A tall and imposing man, he stands well over two meters in height with a broad chest, a thick neck, and pale skin. His black hair is kept neatly slicked back, and his most distinctive features include a long, stitched scar running across his face from the bridge of his nose and a large, golden alloy hook replacing his left hand. He dresses in the style of an Italian mafia boss, often wearing a fur-lined coat over a vest and shirt, sporting several jeweled rings, and smoking a thick cigar. His deep, relaxed voice and characteristic laugh, often written as "gu ha ha ha," add to his commanding presence.

Crocodile's history reveals a dramatic transformation. In his youth, he was said to be a carefree and ambitious pirate who shared the same dream of becoming the Pirate King that many rookies hold. He rose through the Grand Line with great speed, and in his early twenties, he accepted an invitation to become one of the Seven Warlords of the Sea. However, a devastating defeat at the hands of the legendary Emperor Whitebeard profoundly changed him. This loss caused him to lose faith in his dream, becoming cynical and calculating, though he still harbored a deep-seated grudge against Whitebeard. He was present at the execution of Gol D. Roger, an event that shaped the era of piracy.

His personality is a study in cold ambition and cynical intelligence. Crocodile is exceptionally cunning and a master strategist, capable of weaving complex plans that operate for years without detection. He is supremely self-confident, a trait that stems from his genuine strength, but this confidence often leads him to underestimate his opponents. He displays a pitiless nature, showing no hesitation in killing those who become useless or stand in his way. He has a low tolerance for being insulted and a habit of belittling others, frequently using the word "worthless" to describe their efforts. He is utterly pragmatic, viewing trust and faith as idiotic and tools like his former partner Nico Robin as simply means to an end. A notable flaw, however, is his tendency to toy with defeated enemies, leaving them to suffer rather than finishing them off immediately. This arrogance and sadistic streak directly led to his downfall against Monkey D. Luffy, as it gave the determined rookie the chance to recover and fight back.

Crocodile's primary role in the story is as the main antagonist of the Alabasta Saga. Under his public persona as a heroic Warlord protecting the desert kingdom, he secretly ran the criminal syndicate Baroque Works. His motivation was to seize control of Alabasta to discover the location of an ancient weapon, Pluton, which he believed would grant him the military power he now valued over romanticized dreams. He engineered a civil war by using a banned substance to create a devastating drought, framing the beloved king, and positioning himself as the people's savior. However, his plan was shattered by the Straw Hat Pirates, and after three brutal battles, Luffy was the first person to ever defeat him. As a result, he was stripped of his title, his position, and his freedom, and was imprisoned in the maximum-security underwater prison, Impel Down.

While in Impel Down's lowest level, Crocodile's path crossed with Luffy's again. He formed a tense, temporary alliance with the young pirate in exchange for being freed. This led to his participation in the Summit War of Marineford. Though he initially attempted to kill Whitebeard as revenge for his past defeat, he shifted his focus during the battle. Motivated by a cynical desire to not see the Marines "look pleased" and a warped sense of pride that his old rival not be weakened, he ended up aiding Luffy. He protected him from the attacks of powerful Warlords like Dracule Mihawk and Admirals like Akainu, proving his immense power and his unpredictable nature.

Crocodile's key relationships are defined by utility and antagonism. His partnership with Nico Robin was purely transactional until she refused to read the ancient Poni
glyph for him, at which point he tried to kill her. The Revolutionary Army commander Emporio Ivankov is known to hold a secret about Crocodile's past, a weakness that ensured his temporary cooperation during the Impel Down escape. He holds a deep, bitter enmity for Whitebeard, while viewing fellow Warlords like Donquixote Doflamingo with contempt, refusing to be seen as an equal or subordinate. His relationship with his loyal subordinate, Daz Bonez (Mr. 1), is one of the few that approaches mutual respect, as Bonez remained by his side and followed him into the New World. After the Warlord system was abolished, Crocodile took decisive action. He used his vast wealth to fund a new organization, the Cross Guild, teaming up with Dracule Mihawk. They installed the hapless Buggy as a figurehead leader to attract the Navy's attention while he and Mihawk serve as the true ruling powers, with a bounty of nearly two billion berries reflecting his continued threat.

As a fighter, Crocodile is exceptionally powerful. He possesses the Suna Suna no Mi, a Logia-type Devil Fruit that allows him to become, create, and control sand. He has perfected this ability to the point where his body can instinctively turn into sand to avoid physical attacks. In a desert environment, his power is magnified, making him nearly invincible. His signature ability is to drain all moisture from anything he touches with his right hand, turning living beings into desiccated mummies and the ground into sand. He can unleash massive sandstorms like Sables, create high-pressure sand blades like Desert Spada to slice through solid rock, and sink enemies into quicksand pits with techniques like Desert Girasole. His left hand is a hollow golden hook which hides a deadly secondary hook coated in a potent scorpion venom that can corrode even stone. Beyond his Devil Fruit, he is a formidable combatant with powerful physical stamina, having withstood brutal attacks. It has also been confirmed that he can use both Armament Haki, which allows him to harden his body or weapons, and Observation Haki, which grants him enhanced spatial awareness, making him an even more dangerous adversary.