Amphibians, Temnocerans, Snake Wyverns, and large Neopterons are part of why I like 4th gen so much, a lot of unique classes and monsters

The thing with Kappa is that folklore-wise, they're heavily associated with sumo wrestling. They love it, they're unrivaled when it comes to it, and in fact the only way to subdue a kappa is to bow to it, leading it to bow right back like a sumo and pour out its water dish like an idiot. With that context (largely lost with westerners)  I think that while it does feel tacked on, it justifies it a bit in my eyes.

I do agree with your thoughts on Tetsucabra and Zamtrios, but for Tetranodon, Kappa are well known for being sumo wrestlers and they do have shells and bills so that’s where the design comes from

Zamtrios could use their balloon for intimidating predators like Barioth and Tigrex

Tetranodon could eat rocks not only for buoyancy but to also engage in combat by adding to their mass to help push around other monsters like a sumo wrestler

I’d love a salamander monster that everyone thought was a fanged Wyvern until they found out it’s related to the amphibians. Like actual salamanders. Also giving it something to do with lava would just add on to it

19:40 Kappa, sumo wrestler, frog, turtle, and platypus aren't that unrelated. The sumo wrestler, turtle, and platypus elements are all part of its kappa references. Kappa have a turtle-shell-like carapace on their back and are often depicted with beaks (even if they aren't duck-like beaks). Kappa also love sumo wrestling as a pastime despite not having the body type typical of sumo wrestlers. This effectively leaves Tetranadon as only a combination of a kappa and a frog.

As far as the R-rated things kappa do in folklore, those things typically get glossed over in modern-day representations of them, just like how a lot of stories from Western folklore also have similar things glossed over.

the only thing i disagree with is tetranadon, kappas in folklore are said to be fans of sumo wrestling, and the platapus beak helps it stand out as not just a giant kappa

Im suprised you didint mention that Zamtriouses Inflation could also be a intimitation tactic. After all he does it after we the hunters have fought it for a while, its possible that Zamtrious realises we arent worth the effort to eat so he just inflates himself in hopes of making us run away in fear and confusion. Id also belive a Barioth or even a Tigrex whould probably turn back upon seeing a massive blob apear infront of their eyes.

Edit: also 20:14

-Zorah Magdaros will remember that...

One thing that stood out to me about Zamtrios is that curled-up pose it takes before it does some of it attacks. How it makes minor adjustments to keep his curled side facing the hunter. It comes off as a strong intimidation and protective posture, showing off it's size while also protecting it's underbelly. It's easy to imagine Zamtrios doing this to larger monsters like Barioth, and even towards each other.

Though, I can't help but disagree with the comments about Zamtrios and Tetranadon. I don't believe monsters have to have this strict 'do this one idea' philosophy to them. Sure some monsters do that very well, but I believe some should be allowed to just have a lot of features to them. After all, Gypceros has it's rubbery hide, stretchy rat-like tail, and a literal flashbang headcrest that also uses part of his weird beak to use it. I don't see how that's any different from Zamtrios having both ice armor and an inflated state. To me, it exemplifies how MH monsters can be both serious and cool, as well as goofy and charming. To me nothing about it betrays the idea of a 'monster frog shark.'
As for Tetranadon, well, Kappas are a mishmash of many things too. Beak, water plate on their head, turtle shell, webbed feet, and a love for both cucumbers and sumo. Thematically, making Tetra platypus-like is a pretty clever way to interpret a kappa as a animal-like monster. A combination of many aspects rolled into one. And really, I can quite easily see Tetra getting into sumo matches with each other over territory and mating rights, not unlike the shoving and croaking matches some real frogs have.

Either way, good video as always!

Amphibians are some of my favorite monsters, Tetsucabra especially. I love his arenas and the theme of his equipment

I think that the fluid that Tetsucabra use to inflate their tail to use as counterweight and Zamtrios use to armor & inflate themselves is the so called Paddock Oil, the compound exists in both species but it has been specialized differently in each one.

I agree with the Zamtrios sentiment for the most part, while he is my favorite amphibian I don't really care for the inflation aspect, I feel like taking the inflation away from regular Zamtrios and giving it to only Tiger stripe would help focus them and make both better

How i always saw it with Tetsu is that, the bigger his tusks are the more of his babies he could carry there (because i remember hearing somewhere that Tetsucabra carries his young in his mouth).

Also 20:05 : New subspecies! Proctologist Tetranadon, he has a turf war with Magnamalo where he checks up on where all of that hellfire comes from.

Tetranadon is pretty neat for me. I think he'd feel better with more info, like confirming that he has lousy eyesight so that's why he fights the way he does.

Hold up! Kappa are known to challenge people to sumo! Its just Japanese mythology being weird still fits with the kappa theme.

I don't see how Tetranadon is split between multiple ideas when it''s simply platypus and kappa, sumo is part of a kappa's nature so they reference it since it is heavily kappa based, the turtle is also because of it being very kappa-like, although I can see how it feels too much, I think it's fine, the inflation makes it a fun fight so I like it

The amphibians are such goofy fellas, I always find myself smiling when I see them bumbling about doing their stuff.

Especially Zamtrios, he's such a fun one

8:50 That phroge is unreasonably adorable. I love them.

To give an argument for Zamtrios' Inflation, they do share a habit with a wyvern know for constricting it's prey, the Tidal Najarala, not to mention that the ice Clak Clak Lizard, Glacial Agnaktor, might also be a potential predator of the Zamtrios species, since we do see the Volcanic Agnaktor try to constrict Brachydios in the opening of 3U.
But I'm not a biologist, but suddenly getting big would make it hard to wrap around Zamtrios, and Zamtrios does expand quite fast, so if it does feel the vibration of the 2 burrowing wyverns, if it fast enough could expand before the confrontation, maybe even during before they get a good grip!

I would imagine that the inflation of Zam and Tetranadon is related, especially with the idea of zamites filling themselves up with blood.  It seems likely to me that the adult zamtrios use their inflation for intimidation against predators or (more likely imo) territorial rivals, as evidenced by their use of it in combat.  I feel like they would use it more often if it was predation defense, especially since they can already make themselves unpleasant to bite using their ice spikes

something that I think should be pointed out in regards to Tatranadon is that Kappas are described as  weird frog/turtle goblin people, as well as some descriptions mentioning they enjoy sumo and will even challenge people to a match and eat the person if they win. I believe he's actually well executed, and really fits in the world as a whole. Anyway I enjoyed the video as always, thank you for reading if you did and I am genuinely sorry if 1000 other people comment this same thing