Megalo

Megalo (メガロ) is a shark that lives on Fishman Island. He is the beloved pet of the Princess Shirahoshi.

Appearance
He has a usual shark design, the only difference is that he wears a shirt from the Criminal fashion line.

He is several times larger then the usual shark, approximately the same size as the Thousand Sunny, though he is still smaller than Neptune. His mouth is also large enough to cram Shirahoshi into it, but apparently causes great stress.

Personality
For a shark, Megalo is very friendly. He is also very loyal since he willingly went through with Luffy's idea of stuffing Shriahoshi in his mouth to sneak her out of Hard-Shell Tower.

Past
Megalo has been Princess Shirahoshi's pet and the only one who Shirahoshi can talk to during her ten years locked up in Hard-Shell Tower. At some point away from the Ryugu Palace, Megalo ended up getting captured by the Kraken.

Meeting Luffy
Megalo was first seen being freed from the Kraken accidentally when Luffy attacks it. Later, he tells King Neptune about the pirates, and the king invites them to Ryugu Palace, apparently as an act of gratitude. Megalo then carries Luffy and his companions as they make their way to the castle.

He is then seen in Princess Shirahoshi's room while the princess and Luffy are having a conversation. He growls at Luffy for making Shirahoshi cry by calling her a crybaby.

Shirahoshi tells Luffy that she wants to go to the Sea Forest. Knowing that Shirahoshi's size will draw attention, Luffy decides to have Shirahoshi stuffed into Megalo. Megalo then leaves the room with the princess crammed inside his mouth while Luffy stands on top of him. As he breaks through the doors, he knocks out several invading pirates. Megalo copes with having the princess stuffed inside him as he floats out of the palace and towards the Sea Forest.

Incident at Coral Hill
While hovering above Coral Hill, Luffy sees Chopper, Sanji, and a bandaged Hatchan. Once Luffy jumps down to meet them, he is met with accusations from the Fishman Island citizens for mermaid kidnappings. Megalo has finally reached his limit and spits out Shirahoshi. The Fishman Island citizens instantly concludes that this is a Mermaid Princess kidnapping.

The citizens then tie up Luffy and his friends, but are then interrupted by the arrival of Vander Decken IX. After Luffy pummels Decken into the ground with only his legs, Luffy then wakes up Megalo. Megalo then carries the princess, Luffy, and his friends as they attempt to flee the scene. Decken calls out to Wadatsumi to attack them, but Luffy beats back the giant with a Jet Pistol. The shark and the group then continue their path to the Sea Forest.

At the Sea Forest
Megalo eventually reaches the Sea Forest where the group gets acquainted with Franky, Den, and Jinbe. Megalo then rests right next to the Thousand Sunny as Jinbe explains about letting Arlong loose into the East Blue as well as the ideals of Queen Otohime and Fisher Tiger.

Trivia

 * Megalo (Μεγάλο) is Greek meaning "large"; he may be named after the extinct shark species Megalodon.