It is a beautiful sunny day at the Natural History Museum where Tommy and the rest of the class are now making their way through the halls, at the same time that Bogus comes up from Tommy's backpack before he tries to get Tommy's attention, but Tommy pushes Bogus back into the backpack with his finger before the duo continue on their way again. This time, the class then comes upon the Egyptian exhibit as the teacher explains what people did back in ancient Egypt. Bogus is amazed at the prospect of Egyptian history as he quickly rushes off once again and makes his way on top of one of the shelves. At the same time, Ratty peeks in from the ventilation duct before getting hit on the head by the duct.
The teacher continues explaining about ancient Egypt, which then segues into a flashback, explaining about how the pharaoh had a special scarab that he used to gain power over Egypt. After that, the rest of the class continue on their way once again, but Bogus stays behind once again before becoming surprised to discover a likeness of himself on the ancient Egyptian slab. However, when Bogus leans against the slab, it opens up a secret passageway as he falls through, while Ratty charges into the passageway after Bogus, just as the slab closes up once again. One door in a different room opens up as Bogus falls into a golden grail, while another door in the same room opens up and also allowing Ratty to land in a golden grail. Ratty then becomes excited when he sees that he landed in the room of the apparent ancestor of the pharaoh that gained possession of the scarab all those years ago. The kid pharaoh then points at Bogus who then looks over to see Ratty trying to steal one of the treasures in the room, which the kid pharaoh is not happy about.
The kid pharaoh then uses the scarab to bring some forks and spoons to life as they approach a bowlful of berries as they fling them at Ratty, to take care of him. The kid pharaoh praises the forks and spoons for coming to his aid before he decides to take a nap afterwards. Later, the kid pharaoh is sleeping in his bed when Bogus peeks out from some cheese on the table, while looking around at all of the food on the table before he pulls out some feathers from a headdress, which he uses as wings before he starts flying over the sleeping kid pharaoh. However, the feathers come loose, which causes Bogus to fall down, before he starts crawling up the kid pharaoh's chest and approaches the scarab. Bogus tries to take the scarab, but it is still around the kid pharaoh's neck, at the same time that the kid pharaoh's pet cobra comes up, which surprises Bogus, for the cobra is in love with him. The cobra then starts to hypnotize Bogus with her eyes, which leaves Bogus completely at the mercy of the cobra's power.
However, Bogus snaps out of it before using a hypnosis trick of his own as the cobra is also at the mercy of the hypnosis. The cobra then flicks Bogus's hypnotizing pocket watch away before she starts chasing him all over the room. Bogus finds himself cornered by the cobra, but he is able to fight back against the cobra, which leaves her all tied up, as Bogus celebrates his success. With the cobra taken care of, Bogus is able to gain possession of the scarab, but not without waking up the kid pharaoh, as he demands for Bogus to come back with the scarab. Bogus suddenly trips as he falls up against the wall, just as the kid pharaoh starts closing in on him. Bogus finds himself trapped like a rat, before remembering that he can use the same trick with the scarab that the kid pharaoh did with the spoons and forks earlier, as he uses the scarab to animate a pair of mummies that start chasing the kid pharaoh.
Bogus then dresses himself up as an Egyptian pharaoh as he uses the mummies' wrapping to tie up the kid pharaoh, which leaves the mummies as naked skeletons. The kid pharaoh then falls into one of the sarcophagi as it closes on him, before Ratty sneaks up and snatches the scarab away from Bogus. Bogus then starts chasing after Ratty, who starts running across the top of the table before using the scarab to conjure up a horse and chariot in order to make his getaway. Ratty then realizes that he's coming to the end of the table as he falls off before falling off the chariot, which causes the scarab to slip from his grasp. Bogus then catches the scarab as Ratty starts chasing after him, before running back into the wall. A stone slab from the other side of the wall opens up, as Bogus falls out before finding himself in front of a wall inscribed with Egyptian hieroglyphs as Ratty approaches Bogus, wanting to take the scarab back, but Bogus says that the scarab belongs in the exhibit. Bogus then uses the scarab to animate a picture of a lion that comes to life and scares Ratty so much that he runs away, while Bogus starts laughing at his expense. With Ratty taken care of once again, Bogus returns the scarab to his Egyptian counterpart, before the stone slab on the wall opens up, revealing the hand of a mummy that starts beckoning Bogus, which scares Bogus so much that he runs and hides under an Egyptian rug. Bogus then peeks out from under the rug while still rather shaken up.
This time, the class enters an exhibit where all of the greatest inventions of all time are on display. The teacher then starts explaining about the very first telephone, which was invented by Alexander Graham Bell, just as Bogus pops out from the speaker of the telephone. The teacher then starts explaining about the telegraph, which was invented by Samuel Morse, before Bogus jumps onto the telegraph before running over to a display of the Incandescent Lamp, invented by Thomas Edison, before landing next to the display of the first radio, invented by Guglielmo Marconi. Bogus quickly hides just as the teacher starts explaining about the radio to Tommy. Suddenly, Tommy hears Bogus from inside the radio, as the teacher asks him if something is wrong. The teacher and a couple of other kids then leave, leaving Tommy standing alone next to the radio.
Inside the radio, Bogus is now wearing an Elvis Presley wig while singing into a microphone, as Tommy comments that Bogus is not a bad singer at all before he changes the channel on the radio. This time, the channel starts playing country as Bogus is singing country-style music while wearing a cowboy hat. Tommy then grabs Bogus and places him back in his backpack, as he once again scolds Bogus for wandering off again. Bogus then says that he's sorry, before hearing a noise from one of the ventilation ducts, as a trio of Dirt Dudes manage to enter the museum. Bogus has to stop the Dirt Dudes, before stuffing a piece of bubble gum into his mouth as he chews it before blowing a bubble which picks him up and carries him over to where a steam engine is one display, just as the gum bubble pops. Bogus then threatens to show the Dirt Dudes a thing or two, before he finds himself being cornered by a ferocious Doberman who intends to eat Bogus. Bogus then blows another gum bubble which pops, leaving the Doberman with gum all over his face.
Bogus then runs for his life once again as the Doberman starts chasing after him, while also knocking over a sleeping security guard. Back inside the exhibit, the teacher is now explaining to the students about the phonograph, which was also invented by Thomas Edison, which Bogus was hiding in to escape the Doberman's wrath. The Doberman tries to get at Bogus, but he hides in the speaker of the phonograph. Bogus takes advantage of the situation, by using the phonograph speaker to amplify his voice, which scares the Doberman away. Bogus then laughs at the Doberman's expense, before noticing the Dirt Dudes jumping up and down on a typewriter. When Bogus approaches the Dirt Dudes, they just blow raspberries at him, before Bogus jumps up to confront them, as the typewriter platen soars across the air with the Dirt Dudes on it and Bogus trailing along behind them, before landing in the first computer.
Tommy then notices Bogus on the computer screen, but as a rather slightly distorted image, before telling Tommy to take the control so that he can take care of the Dirt Dudes. Tommy obliges as he takes hold of the joystick and controls Bogus to shoot the Dirt Dudes with the phaser. The teacher then asks Tommy what he's doing still in the room all alone as he turns off the TV, forcing Tommy to follow after the teacher. The Dirt Dudes then exit from the computer, before inserting a disc in the hard drive, as Bogus finds himself being shot out at by a monstrous figure on the computer. Bogus takes control of the joystick as the monstrous figure exits the computer and starts chasing after Bogus.
The class is now in front of a display of Christopher Columbus as the teacher then explains to the children that Christopher Columbus was most famous for his discover of America back in the 1500s. Bogus then approaches the display of Christopher Columbus just as the monstrous figure is still closing in on him. Bogus takes the feather pen from the model of Christopher Columbus, and dips it in ink, before using it to paint a hole on the wall, which the monstrous figure runs into and crashes. Bogus then uses a hankie to wipe away the hole once that's over. This time, Bogus is now on the trail of some footprints on the floor, while holding a magnifying glass and wearing a deerstalker's cap, before finding himself cornered by the same Doberman that he scared off earlier. The Doberman then starts chasing after Bogus again as the security guard notices the whole thing. Bogus then climbs up a table that has a TV on display as the Doberman angrily approaches the TV. The security guard then goes over and turns on the TV, showing Bogus as a cooking show host as he inadvertently creates a monstrous blob from the ingredients that he threw into a blender.
The Dirt Dudes are now approached by a janitor as they jump into the trash can, just as the janitor dumps some dust into the trash. Bogus approaches the trash can, demanding for the Dirt Dudes to come out and fight like a man, before the trash can topples over on top of him, allowing the Dirt Dudes to escape once again. This time, Bogus commandeers a small model of an airplane as he takes off before using the plane wheels to scoop up a spray bottle before approaching the Dirt Dudes once again. Bogus then uses the spray bottle to spray the Dirt Dudes as they run away in fear. Bogus then finds himself inadvertently flying towards the Doberman once again who then grabs the tail of the plane with his teeth, before the security guard runs up to the Doberman and takes the plane away from the Doberman. Bogus then starts mocking the Doberman, before the security guard places the model airplane back on its display table once again. This time, the class then enters the room as the teacher starts explaining about the very first airplane, which was invented by Orville and Wilbur Wright, while pointing at the exact same model airplane that Bogus is hiding in. Bogus then says that he served his country well before laughing in celebration afterwards.
Back at the Natural History Museum once again, the class then enters the exhibit where all of the paintings and sculptures are on display, while Bogus is standing on the sculpture of The Thinker. Bogus is wondering how he can go on like this, before the class walks right past him, which prompts Bogus to reunite with Tommy once again, just as the teacher is explaining about how sculpting and art have existed ever since Ancient Greece. After seeing a sculpture of a discus thrower, Bogus reaches into his pocket and pulls out a chocolate chip cookie as he throws it like a discus as it ricochets all over the room before it lands in the teacher's mouth, with Tommy telling Bogus to be more careful next time, while Bogus feels ashamed for what happened.
After the class walks off again, Ratty comes up from the floor grate, followed by Mole afterwards, before the two villainous rodents then approach the Venus de Milo as they start to climb it. This time, the teacher is then explaining to the class about a picture of a pirate ship. Bogus and Tommy are both amazed at the prospect of this picture. The teacher then tells Tommy that he's glad to see him show an appreciation in art. When the class leaves once again, Bogus then jumps into the picture of the pirate ship before assuming the role of a pirate as he boards the ship. Ratty then swings into the painting afterwards as he also assumes the role of a pirate, before he and Bogus engage in a sword fight. Unfortunately, Bogus finds himself standing on the edge of the plank, thanks to Ratty. Outside, Mole is still too scared to swing before he swings into the painting and assumes the role of Ratty's first mate. Unfortunately, he accidentally knocks Ratty off the side of the plank as the two rodents fall into the water, before Bogus starts looking through his spyglass before spying an island off in the distance.
Bogus then dives off the plank and into the water at the same time that Ratty and Mole climb back onto the ship once again, when they see Bogus swimming towards the island. Ratty then orders Mole to get the cannon all loaded and ready. When Ratty orders for Mole to fire the cannon, Mole has a problem trying to pull the cord for the cannon, which causes the cannon to tilt down and fire a blast into the deck of the ship, causing it to sink. This time, Ratty is now standing on the stomach of Mole, who is trying to stay afloat on the water, before noticing Bogus find a treasure map in a bottle. Ratty and Mole start to approach the island afterwards. Bogus starts following the map to find the treasure, but unfortunately, he doesn't watch where he's going as he bumps into a nearby palm tree and falls into unconsciousness, while being watched by a Pirate Parrot. Bogus regains consciousness before noticing the parrot up in the tree, as the parrot tells Bogus that he knows where the treasure is buried. The parrot then flies off as Bogus starts to follow the parrot while Ratty and Mole peek out from some bushes as they have apparently set up a snare trap for Bogus for when he comes to where the treasure is buried.
The parrot was watching from overhead as he flies off and tries to warn Bogus that Ratty and Mole have set up a trap. Bogus then figures out that Ratty and Mole have set up the trap before sneaking up behind the two villainous rodents. Bogus then pulls back a tree branch before letting it go, whacking Ratty and Mole which sends them flying and directly into their own snare trap. Ratty and Mole are left dangling up in the trap as Bogus waves goodbye to them before finding the treasure, thanks to the parrot's guidance. Bogus pulls out a spoon from his pocket before using it to start digging up the treasure in record time. After the treasure has been unearthed (revealing it as a huge treasure chest a lot bigger than Bogus), the parrot then lifts the latch and opens the chest, revealing thousands of gold doubloons inside. Bogus pulls out a pearl necklace before Ratty and Mole approach him once again before they charge in and try to take the necklace from Bogus. What follows after that is a tug-of-war between Bogus and the parrot and Ratty and Mole. Before the tug-of-war can continue even further, the quartet is suddenly approached by a group of tough pirates, as the captain tells them that they found his treasure. He then swings his sword down which cuts the necklace in half, and also sending Bogus flying out of the painting and back into Tommy's backpack once again. Soon, the teacher then tells the class that their tour of the museum is over and that it's time to go home. Bogus then peeks out from Tommy's backpack, saying that he's glad to be going home at last now that that's over.
Absent Characters: Mr. Anybody, Mrs. Anybody, Kevin, Brattus, Aunt Bogunda, Jake and Butch
Tropes found in Museum Madness:
- Angry Guard Dog: The Doberman who Bogus faces off against in the second act.
- Big Ball of Violence: Bogus engages in one of these while fighting against the cobra.
- Bubblegum Popping: Bogus does this twice in the second act. The first time, he blows a gum bubble as a means of transportation when the Dirt Dudes show up, before popping it. The second time was when he does this as a tactic to keep the Doberman sidetracked momentarily, giving Bogus a chance to escape.
- Hoist by His Own Petard: Happens to Ratty and Mole in the third act, after getting sent flying into their own snare trap, thanks to Bogus.
- Human Knot: Bogus fights with the kid pharaoh's pet cobra in the first act, the fight ending with the cobra tied up in knots.
- Hyperspace Holmes Hat: Bogus briefly wears one of these in the second act.
- Hypnotic Eyes: The kid pharaoh's pet cobra does this to Bogus, as sort of a Shout-Out to Disney's The Jungle Book (1967).
- Make Me Wanna Shout: Bogus uses this technique, via use of the phonograph speaker that he's hiding in, to scare away the Doberman that was chasing after him in the second act.
- Nepharious Pharaoh: The child pharaoh who Bogus encounters in the first act behaved this way, after he and Ratty accidentally wind up in a secret chamber hidden within the Egyptian exhibit of the museum. Although to be completely fair, the kid pharoah actually possessed an ancient scarab that had been stolen for many centuries, but Bogus was able to reclaim the scarab and return it back to its rightful place after making quick work of the child.
- Oh, Crap!: Ratty gets one before Mole inadvertently knocks him off the plank of the pirate ship in the third act. He gets another one a little later afterwards when Mole also inadvertently causes the cannon to tip down while trying to fire a shot, before the shot causes the pirate ship to sink.
- Pirate Parrot: One shows up in the third act.
- Reptiles Are Abhorrent: The kid pharaoh's pet cobra in the first act.
- Shout-Out: The way that the cobra uses her eyes to hypnotize Bogus is similar to Kaa's method of hypnosis in The Jungle Book (1967).
- Wingding Eyes: The first claymation short shown during the intro had this happen to Bogus after finding a treasure map in a bottle in the attic, his eyes taking on the shape of numbers before forming the shape of dollar bills.