In Pinocchio, he was animated by Wolfgang Reitherman. He has also appeared in a Bonkers comic and the Kingdom Hearts video games.
Joe Grant's Character Model Department was responsible for the design of Monstro. Models were constructed both of Monstro himself and of his belly, complete with skeleton. In addition, inspirational sketch artist Gustaf Tenggren created a watercolor image of Geppetto in Monstro's belly.
The animation of Monstro was originally to be assigned to Vladimir Tytla (animator of Doc, Grumpy, Stromboli, and, later, Yen Sid, Chernabog and Dumbo), but, perhaps out of worry that Tytla might get carried away, Disney eventually assigned Wolfgang Reitherman to the task. He animated Monstro as a cunning creature with a brain, making his pursuit of his prey all the more frightening. To Reitherman can also be attributed, to an extent, the timing and staging of Monstro's chase sequences, which were timed to suggest the whale's great weight and power. Reitherman drew a set of sketches for a discarded sequence showing Monstro consuming Geppetto's boat; Monstro was to emerge suddenly on the otherwise serene sea scene, first looking like a large mound before revealing his teeth and swallowing the boat in one movement before disappearing underwater once more.
Monstro first appears in this short as the main antagonist. Here, Mickey, Donald and Goofy are about to catch Monstro, but with Goofy's stupidity and Donald's prone-to-frustration, Monstro gets the better of them and they failed, however.
In this Silly Symphony short, when the merbabies are conducting a circus underwater, a sea slug accidentally awakes Monstro and makes him sneeze, blowing the babies and the other sea creatures away.
Monstro is first mentioned in the film when Pinocchio and Jiminy Cricket receive a message from the Blue Fairy who is in the shape of a dove that the whale has swallowed Geppetto, Figaro and Cleo when the toymaker took to sea to search for Pinocchio. The three are still alive, inside Monstro's belly. Against Jiminy's warnings, Pinocchio resolves to find and rescue Geppetto. Though Jiminy tries to dissuade Pinocchio, warning that Monstro is "a whale of a whale...he swallows whole ships!," he does not hesitate to join Pinocchio in his search at the bottom of the sea. The two search for Monstro; mention of his name causes the sea creatures to flee in terror. Meanwhile, in Monstro's belly, Geppetto and Figaro are trying to catch fish to eat. The toymaker tells Figaro that he fears that they will starve in the belly of the sleeping whale.
Monstro wakes at the sight of a school of tuna swimming nearby. Opening his great eyes, he pursues the fish with his mouth open, tearing through the ocean. When Pinocchio sees Monstro approaching, he flees for his life, pushing past the tuna, though he is nevertheless consumed by Monstro. The sprightly Jiminy escapes his jaws, but, on discovery that Pinocchio has been swallowed, tries to enter Monstro's now closed mouth. Jiminy tries to get in but he won't open his mouth. Inside Monstro's belly, Pinocchio, reunited with his father, proposes that they escape in a raft (constructed by Geppetto) when Monstro opens his mouth. When told that "everything comes in...nothing goes out" of his jaws, Pinocchio suggests that they start a fire to make him sneeze.
Monstro once again opens his eyes, this time to find smoke rising from his blowhole. He begins taking deep breaths; while his mouth is open, Pinocchio, Geppetto and the pets try to escape and Jiminy tries to follow them; they succeed when Monstro finally sneezes, sending them flying out onto the sea. After another powerful sneeze, Monstro drank lots of water to put out the fire then, enraged, he pursues the raft while Pinocchio and Geppetto row for their lives. He dives underwater and emerges underneath the raft; Pinocchio and his father row away in time, but when Monstro leaps after them, they are forced to jump into the sea. He smashes the raft into pieces with his tail. Pinocchio saves his father from drowning and pulls him to shore, with Monstro in hot pursuit. As he builds up speed, the waves drifting from the cliffs of the shore hinder Pinocchio. Monstro leaps into the air, aiming to consume and kill the two. Finally, paddling madly, Pinocchio swims through the hole in the cliff just as Monstro smashes into them, the impact of which sends Pinocchio and Geppetto flying onto the beach. As the toymaker comes to, Jiminy, Figaro and Cleo are washed onto the shore. Pinocchio, however, didn't survive the blow. He is later revived, and turned into a real boy, by the Blue Fairy. It isn't clear what exactly happened to Monstro, but it is implied that he was killed after ramming into the cliff, however, this remains unknown.
Monstro had a guest star appearance in a Bonkers comic story titled "Whale of a Tale", published in the December 1994 issue of Disney Adventures. In this story, he is not villainous, but rather a very polite (albeit destructive due to his size) actor who was simply playing a villainous role in Pinocchio and had not found work in the movies since then. He is duped by a gang of crooks, posing as a movie company, into breaking into banks for them to rob, and upon finding out the truth, helps Bonkers catch the criminals.
House of Mouse
Monstro made various cameo appearances on the show.
- In Clarabelle's Christmas List, Donald reels in Monstro when trying to reel in Santa's Naughty and Nice list.
- In Ask Von Drake, Monstro was seen during Ludwig Von Drake's headcount of all the Disney character guests.
- Mickey and Minnie's Big Vacation ends with an advertisement for "Monstro Cruise Lines".
Once Upon a Time
Monstro is seen in Fairy Tale Land chasing Pinocchio and Geppetto. He attacks the raft and leaves.
Kingdom Hearts series
Monstro appears as both a character and world from Kingdom Hearts. Like many of the worlds from the original game, it also appears in Kingdom Hearts: Chain of Memories as well. He 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 have also appeared as an arena for the Mirage Arena matches 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. 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 do 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 appears in Kingdom Hearts as a supporting world, where Pinocchio and Geppetto temporarily live until being rescued. Within Monstro dwell many Heartless, including one called the Parasite Cage, which eats Pinocchio, trapping him within its cage-like stomach, and delivers the puppet to Riku, who wishes to use Pinocchio's heart to rescue Kairi. After Kingdom Hearts is sealed, Monstro presumably returns to his world.
He later reappears in Kingdom Hearts: Chain of Memories, as a figment of Sora and Riku's memories. Monstro himself is not physically seen, but card rooms resembling his bowels are explored.
Monstro appears in Kingdom Hearts Birth by Sleep Final Mix as a new boss in the Mirage Arena.
Monstro appears in his world Prankster's Paradise before it was consumed by darkness. Jiminy and Pinocchio are swimming away from Monstro, but the force of the water pulls them along with Sora into the chaos. Eventually, Pinocchio and Jiminy are then swallowed by Monstro, Sora gives chase on him, but a Dream Eater appears and freezes him in an iceberg that rises the top of the ocean, where Sora follows. He then fights Chill Clawbster on the clusters of the frozen Monstro. During the battle, he frees him, encasing him in a water bubble. Chill Clawbster is soon defeated and swallowed by the whale, while Sora falls into the ocean. Eventually, Monstro then sneezes, blowing him away.
In conjunction, during his adventure, Riku finds himself inside Monstro and spots Geppetto looking for Pinocchio. Riku offers to help find him and also encounter Jiminy, who reveals that Pinocchio ran off with somebody with a black coat. The two spot him walking with that person, revealed to be another Riku as he enters a corridor of darkness without a word. Pinnochio and Jiminy ask if there is anyone that will always be there for Riku. He explains that there is. Suddenly, a vibration happens. Riku orders Pinnochio and Jiminy to head back while he takes a look around, finding the Char Clawbster Dream Eater and destroying it. As Geppetto and Pinocchio are reunited, Riku recalls Yen Sid's words of wisdom and unlocking the world's keyhole. Monstro also appears in Kingdom Hearts and acts as a world of sorts via swallowing the gummi-ship - trapping the heroes in its Heartless infested stomach, while there they also come across Geppetto and Pinocchio, who are still stuck in the belly of the whale.
Kinect Disneyland Adventures
Like in the actual Disneyland park, Monstro is apart of the Storybook Land Canal. At one point in the game, he eats Pinocchio's school books. To recover them, the player must gather some pepper pots to make Monstro sneeze. The powerful sneeze releases them.
Epic Mickey: Power of Illusion
Monstro can be seen in artwork in Atlantica for the upcoming game.
Monstro has a spell card known as "Monstro's Water Spout" in the attraction Sorcerers of the Magic Kingdom.
Pinocchio's Daring Journey
Monstro makes a brief appearance at the ride's climax. Just after escaping from Pleasure Island, the riders are warned by Jiminy that Monstro is approaching. Suddenly, he bursts out of the ocean and lunges at them, accompanied by thunder and lightning. They veer away just in time.
Monstro appears in both versions of the show as a lead-in to Mickey falling into the whirlpool and the stormy ship scene, ending the Dancing Bubbles sequence at the Disney's Hollywood Studios version and coming after the I've Got No Strings scene in the Disneyland version.
Storybook Land Canal Boats
Monstro's biggest appearance is at Disneyland's version of the Storybook Land Canal Boats attraction. Guests ride boats through his mouth, which serves as a tunnel to a land of miniature buildings based on various Disney films.
The guides on the boats state that Pinoccio blew a hole in the back of Monstro to free himself and the others, explaining why he has a hole where his fluke should be. This is far from the events shown in the movies.
- In the original Italian story of Pinocchio, instead of Monstro, it was a dogfish-like sea monster known as the Terrible Dog Fish (Il Terribile Pescecane in Italian), that swallows Geppetto, and then Pinocchio.
- At the time Collodi told this monster story, many Italian mothers would tell their children not to swim to far out to sea or else this terrible phantom shark would swim up and swallow them.
- In Collodi's story, the monster is described as being larger than a five story building, a kilometre long (not including the tail) and sporting three rows of teeth in a mouth that can easily accommodate a train. So fearsome is its reputation, that in chapter XXXIV, it is revealed that the Dogfish is nicknamed "The Attila of fish and fishermen" (L'Attila dei pesci e dei pescatori in Italian).
- Monstro has the the body shape and teeth of a sperm whale, but has the size, skin color, and underbelly of a blue whale.