I was looking at all of Universal's older catalog under the 'monsters' banner when i originally thought of the Metaluna Mutant and Mole People, but i came across "Tarantula" and i started thinking in this same kinda camp the same way Unchained is.
THE LOST VOYAGE
Setting:
Darkmoor Harbor and Shipping Co. on the edge of the swamp. A lagoon connects the ocean to Darkmoor's port.
Context:
It's always been rough getting outside shipments to come into Darkmoor due to its 'DARK' legacy, but this time, specific cargo for Victoria Frankenstein's experiments have gone missing and she's hired a team of shady and otherwise unscrupulous individuals to seek them out. You must venture into the swamps that lie between the ocean and Darkmoor's dock to seek out the lost shipment, as therein lies a tool paramount to the experiments going on in the Frankenstain estate castle. Who knows what goes on in there and why this is so important to Victoria, but we know she pays well, so we don't ask too many questions...
Characters:
Captain Maia - A haggard sailor, brave enough to have taken the order from the dockmaster and shipwright running the yard, despite all of his awful experience in the swamps throughout his life. He looks like a cat with nine lives who has run out of eight of them and you're not quite sure if he's all there, based on how he carries himself. He's had run-ins with a creature that stalks the lagoon before and he's lived to tell the tale to anyone who would listen, so he's coming along not just for the money but to make sure no one dies along the way; He's barely altruistic enough to admit as much out loud, if only to afford another bottle at the locale watering hole.
*If people want a character to show up in the "cantina" that many people liked @DrStarlander idea of being in the same mini-land as this indoor/outdoor ride, this is the character i'd suggest do a mini-show sequence, as the wisened old sailor is a stereotype for a reason. He can tell a series of stories of different monsters he's met in Darkmoor, not just the swamps, and how he may have been hired at one point to procure a certain coffin containing a certain individual back in the day. This isn't the amazon, but we still have a Creature, and where there is a Lagoon, we need a boat, and a boat needs a Captain.
Doctor Henry - A shady and quiet doctor conducting field research for Victoria, he hopes to find a specific algae native to Darkmoor swamp that a certain creature has been known to feed on to survive. The Captain warns him that this journey is not for those 'too busy with their noses in their books', and as much as he finds his nose in bottles - not the kind Henry is lugging around. The good Doctor promises the apprehensive Captain that he's not all 'brains' and that he has a couple tricks up his sleeve to take care of himself.
*Henry is, of course, Henry Jekyll but the audience wouldn't know that up front. Halfway through the ride, Henry would find what he's looking for and go to claim it but manage to get captured by Gillman in the process and 'disappear.' We think he's done for, so we keep moving, but we eventually get stuck in the downed ship debris macguffin we've been searching for. While trying to disconnect their cargo, he shows back up in time to take one of the potions he's been carrying in his bag and dislodge us from our predicament when he goes HYDE. In my head, Hyde would be more animalistic and gorilla-like, to really lean into the beastly side of it. I'm not sure if Henry would be a character they'd show walking around or in the cantina as much, but i could see him finding a place on the ride if you make it make enough sense.
Herbert "Herb" Griffin - A no-good rapscallion swindler type with a skin condition, so he keeps his face hidden; It's all a part of his schtick because he claims to be the greatest burglar the world has ever seen, so he can't let anyone see his face as he'll always have plausible deniability. He's always cracking jokes at the expense of the crew(and audience) but we all know he's in it for the money. As a foil to the Captain for all the wrong reasons, Maia is even more apprehensive about bringing Griffin because he can't be trusted, he calls him the "Invisible Man" to his face and Griffin just laughs(but doesn't disagree). Even if he is the biggest and bestest thief in all of Darkmoor, always bragging about how he will never get caught, he will have to prove himself useful to this expedition if he wants to get paid.
*Griffin is obviously the Invisible Man, and he will look so in appearance, even down to the face-wrapped bandages and shades. I'd want to bring in the more adventurous side of his appearance as a character in the land(he kinds looks like Rorschach and Negative Man had a baby imo) and less a mad scientist, as we already have so many of those running around. I realize i'm leaning into League of Extraordinary Gentleman territory a little bit here with my characters, but it ain't broke. This is essentially a mission into a dangerous place to procure misplaced goods, and Griffin can fit that bill. I think he'd work best as someone who reveals his hand earlier on in the ride, de-masking and going through the situation outside of us if only to prove the Captain right and make for a cool floating clothes visual gag payoff when we need to find the cargo we've been looking for. The real drum-cymbal ba-dum-tiss moment is that the Captain will openly remark at the end of the ride that he hopes wherever Griffin is, he's burning for abandoning them when they needed him most, to which Griffin will be heard -laughing- saying, "I've been here the whole time."
Creatures:
Gillman - The monster of Legend, stalking the swamps but also it's unbeknownst protector. Not the reason the original boat sank, but blamed for it all the same. He has territorial disputes with the other creatures in the swamp, but stands tall as the most agile and adept for the surroundings. He gave the Captain his most notable scar, and the Captain has been chasing that revenge-high ever since. He will look the same, if not more imposing than the Unchained attraction. Entering the swamp, he makes several background appearances before getting one of those JAWS up close moments attacking the boat and trying to drive it away, back where it came, and this is where i'd say Henry gets nabbed. The Captain knows where the creature is taking him, and he assumes it's where the wrecked cargo ship is too. In truth, Henry will reveal that the Creature was trying to keep people out of the swamp and he was able to find what he's been looking for in it's lair, promising to leave as soon as he got what he came for.
Mole People - In one scene, passing through a cavern, beady luminescent eyes will surround the boat and a scurrying can be heard. The Captain lights up a lantern, revealing you've been absolutely surrounded by them - they will appear smaller, more mammalian, mandible toothed humanoid creatures. They will turn and hear something else approaching in the cavern, and flee, to which i would want to interject with...
Tarantula - The biggest god damn spider you've ever seen. This is when i'd say Griffin says, "I didn't sign up for this. Spiders are where i draw the line" (his fear of being "caught") and bails.
Metaluna Mutant - When leaving the caverns, we come face to face with a large destroyed cargo ship with a hole punched through the side of it. The Captain will remark that this isn't the doing of Gillman, but something else, something he's never seen before. Our boat is small enough to float through the hole, and we enter the drowned cargo hold. This is where we get "stuck" but in reality, we're being held by the MM, who reveals itself, and in it's clutches, the 'tech' Victoria needs to complete her experiment (for purpose of being hand-held, let's just make it 2x2 metal box of unknown origin). The MM would be alien-like in its appearance (maybe -if only- to get those ExtraTERRORestrial feels) and the Captain would remark that it's 'not of this world.' This is when Gillman fights the mutant to claim Alpha territory of the swamp, protecting us at the same time. This is ALSO when Jekyll shows back up and goes HYDE to get us out of there and aid the Gillman in drowning the MM. Gillman and MM go into the water, only Gillman comes out. He looks at us once more, Jekyll now back to human form, explaining how he made an agreement for us to leave and never come back into this side of the swamp -into "his" territory- ever again. The Captain looks on in bewilderment, never having expected to be saved by what he thought once haunted him for so long. Reluctantly, but with macguffin in hand, Maia turns the boat around and brings us back to Darkmoor - a couple scratches here or there, but enough to tell a tale or two over a bottle of grog.
*The ride either begins and/or ends with an outdoor sequence, making it feel like the boat is leaving/returning to Darkmoor*
The End - exit through the harbormaster's unclaimed freight - visit the cantina for some hair of the dog, if ya dare.