Monstro is both a character and a world that appears in Kingdom Hearts, taking the form of the insides of a giant whale. Like many of the worlds from the original game, it also appears in Kingdom Hearts: Chain of Memories. Monstro is an immense space whale that swims the Lanes Between, so large that its innards are a world to themselves, similar to Deep Space, and also appeared in the Monster of the Deep battle in Kingdom Hearts Birth by Sleep Final Mix.
However, despite its monstrous size, it is actually fought as a boss in Kingdom Hearts Birth by Sleep Final Mix, in an oceanic arena seemingly based upon Pinocchio's world, Prankster's Paradise. Although Monstro is considered a world, it lacks a Keyhole, and its mobile nature means that Sora and his friends cannot always reach it whenever they try.
Monstro is one of the few worlds in Kingdom Hearts that does not need to be cleared to beat the game, but Geppetto and Pinocchio will not appear in Traverse Town until it is completed. Furthermore, if the player waits until they have cleared Hollow Bastion to venture through Monstro, Riku will not appear in any of the world's cutscenes or battles.
Monstro is unique in that it is a both a world and a character. Plus, this means he is the only world from another world, Monstro's homeworld being Prankster's Paradise.
Sora, Donald, and Goofy are flying away from Agrabah to get to their next destination, when they spot something huge flying towards them on the Gummi Route. They quickly realize it is a massive whale, but cannot get out of the way before the beast swallows their ship whole.
Inside Monstro's flooded mouth, the trio finds Pinocchio again and meets his father Geppetto in a broken ship. While speaking with Geppetto, Pinocchio slips off to explore Monstro. Sora and his party quickly run after the puppet into the bowels of Monstro. There, he finds Riku; the two friends exchange some quick words before Riku runs off with Pinocchio, hinting at Riku's newfound darker nature.
Sora, Donald, and Goofy chase the two through the whale, until they eventually finds them in a large circular chamber: the bowels of the beast. Pinocchio is taken captive inside the Parasite Cage Heartless. Sora and Riku team up to take down the Heartless, but are unable to completely destroy it. Riku takes Pinocchio; his words hint to Sora that there is something different about his old friend. Sora tracks the puppet to the Stomach, where Riku and the Heartless attempt to take Pinocchio's heart, but fail. Riku flees as Sora enters the belly of the beast where he defeats the Parasite Cage once and for all and rescues Pinocchio.
From all the commotion in his organs, Monstro spews out the Gummi ship and the trio to prevent any more trouble. Pinocchio and Geppetto also escape and set up a shop in Traverse Town.
There are alternate cutscenes for this world if the player chooses to complete Monstro after the defeat of Riku and Maleficent and sealing the keyhole in Hollow Bastion. Instead of Riku helping to fight the first Parasite Cage, Sora will fight only with Donald and Goofy. Once Riku abducts Pinocchio, he leaves the mouth area as soon as Sora arrives, preventing his face from being seen. Once Sora makes his way to the Stomach, he questions what Riku is doing. Riku replies by asking if Sora remembers his best friend or not. Sora accuses Riku of being a fake, knowing what has already become of Riku after his visit to Hallow Bastion. Riku does not reply, instead the Parasite Cage arrives and Riku uses a dark portal to leave the world.
Chain of Memories
Sora, Donald, and Goofy visit a recreation of Monstro in Castle Oblivion. There, the three meet Geppetto who is hoping to find his son, Pinocchio, who went missing. When Sora finds Pinocchio, he tells them that he is trying to find a way to get them out of Monstro, but is not having much luck. As they chase after Pinocchio he is caught by the Parasite Cage.
The party again fights the Parasite Cage, though only once this time. Pinocchio is told to be brave, and his struggles eventually getting him out of the Heartless's maw-like belly. Sora, Donald, and Goofy then fight several Shadow Heartless in order to make Monstro spit out Pinocchio and Geppetto, as per the puppet's suggestion that a big enough struggle would cause the whale to sneeze. This fight is treated as a mini-game, making Monstro the only world to have a mini-game besides 100 Acre Wood.
Kingdom Hearts 3D: Dream Drop Distance
Monstro appeared during Riku's visit to Prankster's Paradise. Riku had engaged in a mission to find Pinnocchio for Geppetto, and eventually found him, at the hands of a hooded figure who could possibly be his own Replica. Before getting any explanations, a huge tremor occured inside Monstro, forcing the figure to leave and Riku to let both Pinocchio and Jiminy behind. After Riku defeated the Dream Eater that was fighting Sora, reversed with elemental powers, he came back and sealed the world's Keyhole of Sleep, which was inside Monstro's mouth.
Monstro is so enormous that its playable map is bigger than that of some other worlds, like Wonderland. If one leaves Monstro and tries to go a different direction, then they will be caught by Monstro again and Monstro will appear twice on the map. Sometimes, attempting to return to Monstro will not work, as Monstro will temporarily leave his spot; Goofy will express his relief at this and the party will have to come back later.
Monstro has one of the most confusing layouts of any world; it is essentially an interconnecting maze. It takes a lot of patience and a little ingenuity to make your way all the way through. Many openings open into different parts of the same room, allowing for much confusion of anyone trying to work their way through.
As the surfaces in each area look the same, the only visual differences in the Chambers are the ledges, the treasures, and the occasional Barrel and debris found in them. In addition, the Chambers are marked only with numbers and are not traveled through in numerical order. Finally, Monstro defies anatomy as it is known, so natural assumptions such as going "down" to reach his stomach, for example, do not hold (you have to climb up his throat.)
Sora and his party enter through Monstro: Mouth, the largest room in the world. Here, among the piles of wood and shipwrecks, the party will come across Geppetto and Pinocchio, as well as the world's Save Point. Troublesome Pinocchio leads the party down the into the whale's innards. Monstro: Chamber 1 is the arrival point for the party here. The lowest door leads to a dead-end at Monstro: Chamber 3, marked by a large piece of debris blocking off the other lowest exit.
The door on the ledge of Chamber 1 will take the party to Monstro: Chamber 2, which leads to Chamber 3 going down, and to Monstro: Chamber 5 going up. Monstro: Chamber 6, which comes soon after, stands out because it is formed like a set of stairs. Chamber 5 will also send the party to Monstro: Chamber 4, from which the Monstro: Bowels and the first battle with the Parasite Cage can be found, as well as a Save Point.
Returning to the Mouth and using High Jump, given by Geppetto, the party can at last reach the Monstro: Throat, a tall, pink chamber with a series of ledges to ascend. At the top, the party can reach the Monstro: Stomach and the second boss battle against the Parasite Cage.
In Chain of Memories, there are extensions coming out of the floor which can be hit or jumped on to gain items. There are also extensions from the walls which can cause damage to Sora or Riku if approached; these can be hit to gain HP orbs.
Monstro is a boss exclusive to Kingdom Hearts Birth by Sleep Final Mix. It is fought within the Monster of the Deep battle. The battle will be made up of a timed stage where the player can attack Monstro directly, and an acid-filled stage within Monstro's belly where the player is sent once the three minutes run out. The player must defeat the Unversed within Monstro to escape and try to damage Monstro further.
- Monstro swallows the character into his belly, and force the character to battle Unversed in order to get out. The battle will start at his belly, but if it does happen again, the area will be filled with acid, that can damage the character.
- Monstro jumps out of the water to swallows the character, and then shoots the character out of his blowhole.
- Monstro slams the water to create damaging tidal waves.
- Monstro body slams the island that the character is on to cause damage.
- Monstro swings his powerful tail down on the character.
- Monstro charges at the character's direction to knock the character off the island.
- Monstro attempts to inhale the character in and spits the character out, if successful.
Monstro is a unique Mirage Arena boss. The battle begins in a stage within Monstro's belly where the player must defeat the Unversed within Monstro to escape. Once all the Unversed are defeated, the true battle begins as Monstro spits the player out.
Monstro is a tough opponent in battle as he has high HP, and compounding the difficulty is the fact that the player is only given three minutes to damage him as much as possible and the arena consists of small islands. In terms of offense, Monstro will slam the water to create large, damaging tidal waves. the boss will also body slam the island the player is on to cause large damage, as well as slam his tail down on the player.
Monstro will charge directly at the player to knock him or her off the island. And lastly, the boss will attempt to inhale players in, and if successful, spit them out via the blowhole, causing damage. The player can stop this attack by throwing an explosive barrel at him, knocking him out. At this time, the player can cause the most damage to Monstro.
To damage Monstro, the player can throw the explosive barrels at him when it rises above water, and should use distance attacks such as Shotlocks, and fire commands. The best way to damage him is to use Mine Square and/or Mine Shield. When his body slams or slams his tail to you, dodge it and then use Mine Square. After three minutes of combat, Monstro will swallow the player, where he or she must defeat the Unversed to escape and damage him further. However, the arena is now filled with acid, which can damage players. By repeating the above strategy, Monstro will fall with relative ease.