Surume

Surume is a Kraken which dwells in the deepest parts of the ocean, and is a subordinate of the New Fishman Pirates, but temporarily became Luffy's pet. Luffy is the one who gave Surume his name.

Appearance
Surume is a massive, boneless, octopus-like creature several hundred times larger than the Thousand Sunny. Unlike a regular octopus, it has a turtle-like head without a beak between the arms. Surume has at least 18 tentacles (more than double the number of a regular octopus)

Abilities and Powers
Due to his size, he has shown himself to be very powerful, with his tentacles long enough to crush several ships in one swipe. He was also shown destroying a ship bigger than the Thousand Sunny without any effort and knocked out Wadatsumi with just one punch. He was called the "Monster of the Arctic" by captain Vander Decken.

Like an ordinary octopus, he can regrow severed tentacles. Apparently, this ability to regenerate seems remarkably quick, evident since Zoro reduced at least one tentacle into strips, only for Surume to appear once again with all of its tentacles intact after being tamed by Luffy.

Personality
Never knowing satisfaction where killing is concerned... It is a demon, running about the great deep and preying on ships!! The enemy of the human race!!! When the Straw Hats first encounter one on their way to Fishman Island, several crushed pirate ships can be seen between its massive tentacles, indicating that it feeds on the ships and crew it pulls down into the ocean. Caribou found it odd that one would be living near the Red Line. Surume is actually quite intelligent, knowing a threat when he sees one, such as when he attempts to attack Luffy as he was preparing his Gear Third attack, knowing that he'd be a threat if he didn't.

His personality appears to have become more playful after Luffy tamed it, such as when he placed the Thousand Sunny on top of his head, and he seems to be able to understand human language. Whether Surume is following Luffy out of respect or fear is unclear, though he does genuinely seem to be happy to follow orders. He also appears to be forgiving, ready to follow orders from Luffy, despite the fact that Luffy led two others (Zoro and Sanji) at completely decimating him only mere moments ago. He also fears the New Fishman Pirates, as he immediately dropped the Thousand Sunny and went into hiding.

Fishman Island Arc
The Straw Hat Pirates first encountered a Kraken at the entrance of the Downward Plume on their way to Fishman Island. The massive creature apparently had taken shelter there while feeding off of the passing pirate ships attempting to make their way through the Red Line for the past few days. Several crushed ships can been seen clutched between its tentacles. Gyro and his crew only managed to get past the Kraken days before due to it being asleep.

While the rest of the crew comments on the creature's sheer gargantuan size, Luffy, undeterred, expresses his wish to "tame the little guy" with excitement, much to Caribou's shock. Soon Coribou and the other Caribou pirates arrive and the Kraken destroys their ship.

Luffy, Sanji, and Zoro left the Sunny in Flutter Kick Coating bubbles introduced by Caribou in order to fight the Kraken without bursting the protective bubble around the Sunny. Before they begin their assault the Kraken attempts twice to crush the Thousand Sunny with it's tentacles but is thwarted once by "Franky Rocket Launcher" and a second time by Chopper's new and improved "Guard Point".



Sanji burned one of the Kraken's arms off with Diable Jambe, followed with Zoro severing one more with a new Santōryū technique. This infuriated Luffy due to his desire tame the Kraken as a pet. Luffy then used Gear Third and imbued the attack with Busoshoku Haki. The attack knocked out the Kraken even while Luffy was being severely weakened by the seawater. It also caused the sea monster to release Megalo, which it had swallowed earlier. The Kraken is then carried by the Downward Plunge into the blackest depths of the sea along with the trio.



Later however, when the remaining Straw Hats are under attack by Vander Decken and the Flying Dutchman, the Kraken appears and takes out the umibozu Wadatsumi saving Thousand Sunny's bubble from bursting. It is then revealed that the Monster Trio had tamed the Kraken and that Luffy had named it Surume. However, as soon as the crew became acquainted with the Kraken, the undersea volcano erupts.

The resulting eruption causes both parties to retreat from the volcano, with Surume literally running across the ocean bed. On Luffy's command he jumps into the ravine, but is still pursued by an avalanche created by the eruption. He and the crew are saved thanks to Usopp's Pop Greens, though Surume gets knocked out by a stray boulder. When he comes to, they find that they are extremely close to Fishman Island. Suddenly the Straw Hats are surrounded by gigantic sea monsters as large as Surume. This causes Surume to drop the Sunny and hide, showing his fear of the New Fishman Pirates.

As the Straw Hat Pirates are launched into Fishman Island, Surume looks at them, while being surrounded by the sea creatures.

Major Battles

 * Surume (then unnamed) vs. Caribou Pirates
 * Surume (then unnamed) vs. Monkey D. Luffy, Roronoa Zoro, and Sanji
 * Surume vs. Wadatsumi

Trivia

 * "Surume" (鯣) is Japanese for "dried shredded squid".
 * Surume resembles the other giant octopus in the series, the Mori Dako, in both looks and fighting style; only Surume is several times larger.
 * In Norse mythology, the Kraken is a legendary sea monster of gargantuan size that is said to have dragged dozens of sailing vessels down into the ocean to devour its crew.