The name "Bugsnax" being named after snacks. Just like how most snacks are bad for you in real life, the Bugsnax are bad for Grumpuses. And just like how some insects are parasitic breeders (like the green-eyed wasp in Europe), the Bugsnax are parasitic breeders.
Considering the mind-altering properties of Bugsnax, what you've been doing for the side-quests the whole time makes perfect sense. Like Lizbert said; they tempt you. Most all of the townsfolk, one way or another, try to solve their problems through Bugsnax, like Wiggle requesting Bugsnax to make up for her supposed lack of inspiration. They all want a magical solution to their issues. The "Shaggy Dog" Story endings to their sidequests make them realize that Bugsnax aren't the solution, which allows them to resist eating and actually fend off the Bugsnax in the finale.
While Bugsnax are largely viewed as a metaphor for drugs and drug addiction, they also serve as a great metaphor for addiction to one's own passion. Each of the Grumpuses are obsessed with something in particular: Chandlo is obsessed with fitness, Beffica with gossip and snooping, Cromdo with getting rich quick, Wiggle with music and wanting to be a star, etc. All of them want Bugsnax because they believe that those things can give them exactly what they want. But instead, all the Bugsnax do is turn them into stereotypes of themselves, defined only by their passion, and they feel very unfulfilled as a result. When the Grumpuses learn to resist Bugsnax, they become more complex as people, with more ambitions and goals in life. Therefore, a major moral of the game is that being obsessed with something — even something you're passionate about — is not healthy, and living a more diverse, open-minded life is ultimately far more fulfilling in the long term.
Wambus points out that you can't cook Bugsnax — they turn into flavorless mush if you try. This makes more sense in light of their true nature; they can't assimilate you if they're already dead, after all.
The Journalist is allergic to Bugsnax. They're also the only Grumpus to get actively attacked or avoided by any Bugsnax. Pay attention during the side-quests and game events, and you'll notice that not once do any of the Bugsnax target any Grumpus but the player. If they ever even touch one, it's on accident, such as a Bunger ramming into Filbo after Wambus throws ketchup on his face. Seen this way, their behavior makes perfect sense. Bugsnax, at most, are difficult to catch for the others. It wouldn't make sense for them to actively discourage their consumption all the time... But you? You're dangerous. You cannot be affected by Bugsnax. Of course they want you gone.
Alternatively, it's because The Journalist doesn't have any inner turmoil or hidden issues that the Bugsnax can exploit. They have no "hole inside their soul" that they can fill with themselves. Lizbert and her expedition each had their own secret desire or fear or obsession that Snaktooth Island could prey on and manipulate with Bugsnax, that's why all of them find Bugsnax so tasty. Not The Journalist. They don't have any self-doubt or secret fear that the Bugsnax can prey on. They're the only one who finds Bugsnax awful and tasteless because their body rejects them, or more accurately, the parasites reject them because they can't be swayed.
That's not really true though. The Journalist, if they weren't made into a player insert, would definitely have their own fears. Specifically, their job being on the line and the likelihood of them feeling like a fraud or failure like Wiggle and Wambus respectively. It's definitely something the Bugsnax could easily exploit. As such, The Journalist being allergic to them is likely a coincidence in-universe and not based on lack of insecurities/obsessions.
While the above is true, what separates the journalist from the other grumpuses is that they have a concrete goal. The grumpuses each have something they want, but no actual plan on how to get it besides "maybe Bugsnax will help". For example, Cromdo wants to get rich, and decides to sell Bugsnax, but can't get off the island to do so, doesn't know how to transport them, breed them reliably enough to have a market, or even convince any of the other grumpuses to buy anything. The journalist has a concrete goal of finding Lizbert, interviewing her and writing an article about her findings. While they can also write about the Bugsnax, they wouldn't seem credible without an "expert," such as Lizbert. While they could bring a Bugsnak back with them as proof, live specimen handling isn't their specialty, seeing as they didn't capture the Grumpfoot. Interviewing Lizbert is their main goal and will solve the problem of losing their job, and unless the Bugsnax will lead them to her, the journalist doesn't need them. Hence why they are immune.
Related to above, the reason why Filbo is the only other Grumpus that can't die on the island? He doesn't have any issues like the others. He came out of loyalty to Lizbert and the only time he asks for Bugsnax is when he's literally starving. Beffica even says that he doesn't like Bugsnax, he just eats them because everyone else does. While his self-doubt means that he isn't allergic to Bugsnax, he knows that Bugsnax won't help and can therefore resist them.
In addition to this, the other possible reason for his resilience is the core reasoning behind his doubt being born out of a selfless fear; namely, his incompetent leadership and his inability to help people be happy and content. Every other person who was more negatively affected by Bugsnax had ultimately selfish intent behind their desires, which meant they were more easily isolated and mentally affected. But Filbo knows that Bugsnax can’t compensate or improve his lack of leadership skills or his inability to help people outside of just helping feed people, and thus wouldn't make the former Snaxburg residents accept him as a leader or as a friend.
Another reason why Filbo, Lizbert, and Eggabell can't be seen getting assimilated? They all know the truth about Bugsnax, whether via Liz's word or via direct experience.
Filbo's sudden change back to his usual self-deprecation when told to leave Lizbert and Eggabell behind can seem a bit sudden, especially after he showed that he was capable of being a good leader. But it makes much more sense when you consider that he might have thought that his leadership position would only be temporary until the "real leaders" returned. Having his two leader figures basically tell him that they can't return with him probably threw him off, that he would have to be leader permanently because he only saw (and believed due to his past failures) that his leadership would be until better leaders came back, and never considered that this might not be possible anymore.
A more meta example; the KKB song contains the lyric "Come to Snaktooth Island and discover, it's Bugsnax!" Not "Its Bugsnax", as in, the Bugsnax within the island. But... "It's Bugsnax". Snaktooth Island literally is Bugsnax. The biggest twist in the game was revealed in a promotional song in the most inconspicuous way possible while also appearing as an extremely common grammatical error. That's some skillful planning right there.
The game's very first announcement trailer changes in meaning entirely after knowing the truth behind Snaktooth Island. Lizbert's recording speaks nothing but praise about Bugsnax, but cutting to sometime later, the Snakfoot golem tries to attack the camera — Liz herself was trying to destroy the recording, to make sure it reached no one and the island didn't trap even more Grumpuses.
Cromdo LITERALLY has a bridge to sell you. He's a literal conman.
Triffany, after getting the journalist to feed her some live Ribblepedes, mentions how they're "squishy all the way down". While intended to note that despite their appearance, they don't actually possess any bones, this makes sense once you learn what they really are; they can't assimilate you if you only eat part of them.
Wiggle’s hut has a Grumpawamba record in it, which when scanned reads “With hits such as ‘Grumpthumping’ and nothing else”. While this can easily be read as a Take That! moment towards the real life band for having only one recognizable song, the joke is also a rather fitting description of Wiggle’s own music career, which has hits such as “Do The Wiggle” and nothing else.
Why is it that Sprout is able to avoid being affected by Snaktooth's control compared to the rest of its fellow Bugsnax near the end of the game? Because of two major factors:
One: It was stuck inside of the buggy ball, which might have provided an extra layer of resistance for Sprout to ignore the call of Snaktooth.
Two: It's clearly much younger/more recently grown compared to the others, given its coloration, and thus it was more malleable to the influence of outside forces like Gramble. By contrast, the other Bugsnax seem to be full adults, and thus are fully ingratiated into the Snaktooth Hive Mind, thus meaning they can't be made to fight against their own nature like Sprout.
Ironically, this means that Gramble is potentially onto something with taming the Bugsnax, but his mistake is trying to tame too many Bugsnax at once, and all of his choices were clearly fully grown and thus too inflexible and integrated into the Hive Mind of Snaktooth to change.
As many know, completing a character's sidequests means that they won't eat any snax in the ending sequence. Many state that this is simply that they know they don't need them anymore, but it's even deeper than that. Listen to their dying lines and realize how that connects to their sidequest lines:
When Shelda dies, she brags that she's powerful enough to resist the Bugsnax, even when it's clear that she isn't. When you complete her sidequests, she realizes that she's just as flawed as the others, gives into temptation quite easily, and most importantly, people know that's the case. Knowing that, she doesn't even try to overpower the Bugsnax, and instead stops herself from eating them.
When Floofty dies, they state that Bugsnax are the key to finding the very nature of being, and they need to indulge. When you complete their sidequests, Snorpy finally puts his foot down and enforces an upper limit on how far they should be experimenting on themself, and that risking their own life to find out about Bugsnax is not worth it. As such, they sacrifice the knowledge to save themself.
When Chandlo dies, he vows to take in the Bugsnax to become strong enough to defend Snorpy. When you complete his sidequests, he realizes that Bugsnax do not make him any stronger, he'll eventually hit a point where he can't get stronger, he comes to terms that he himself cannot protect Snorpy alone, and Snorpy has the power to fend for himself if need be. Accepting that, Chandlo uses his current strength to survive.
When Snorpy dies, he accepts that his knowledge is much too dangerous for him to know, and that the only way to keep those secrets is to the grave. When you complete his sidequests, a fight with Chandlo causes him to realize that keeping these secrets even when he's worried sick about him is only hurting Chandlo more than if he knew the secrets. So he lets it all loose and openly fights against his Grumpinati adversaries.
When Beffica dies, she laments that she has no friends, and she can't trust anyone enough to try to make new friends, so she gives herself to the only things she trusts: Bugsnax. When you complete her sidequests, Chandlo breaks her distrustful worldview and causes her to realize that not everyone has some deep dark vice she can exploit, and even if they do, letting it be known is not helping anyone, not even herself. So she pushes on, resisting her death to make a new life for herself.
When Cromdo dies, he denounces his fellow Grumpuses in favor of making it big with Bugsnax. When you complete his sidequests, he realizes not only are Bugsnax not that profitable, but sacrificing morals for moolah isn't working, try as he might. So he fights back against this Ponzi scheme, paving the way for achieving his passion instead of profits.
When Wiggle dies, she collects all the muses she can, so that she can truly make her magnum opus, one last song for the Bugsnax she loves. When you complete her sidequests, she realizes that no matter what Bugsnak she eats, be it a beautiful white Cheepoof or a mighty Megamaki, they cannot respark her glory. So she doesn't try any further, pushing the snax back so that she can find a new muse.
When Gramble dies, he promises not to leave his new family, seeing them as the only true people that will stay with him forever, and not just leave him behind for no good reason. When you complete his sidequests, the Bugsnax he raised do exactly that, making him realize they don't love him nearly as much as he loves them. It's hard for him to accept, but he chooses to stick with Wiggle and not give in to the "family" of Bugsnax.
When Wambus dies, he cries that he's a failure through and through, and feels like nobody should believe him. When you complete his sidequests, while he still calls himself a failure, he quickly gets over it and accepts that his sauce garden is enough of a success that he can believe himself. He won't let himself fail. He. Won't. Quit. So he doesn't give in to his hunger.
When Triffany dies, she accepts that her death was inevitable, and rather than delay the inevitable, she falls to the only true staying power to the island, even if her body is never found. When you complete her sidequests, she comes to the realization that Bronica Lottablog's story was never truly finished, as her final moments could be anyone's guess. She doesn't want her own life to end in one big mystery too, so she pushes forward, making sure her story has a proper conclusion that people will discover.
The Grumpinati plotline mirrors the real-life Illuminati: it really did exist in the past, but is long extinct. Some people believe they wield world-scale power to this day, but while there are indeed incredibly powerful and manipulative people in the world (as demonstrated by a prominent contribution to Snorpy's issues), they're decidedly more believable.
Bugsnax can't assimilate you if you try to eat part of them... which is why even the soda cans, kiwis with spoons attached, and French fry cups are Swallowed Whole.
Shelda is a sorta new age, alternate medicine-believing older woman who doesn't trust in Bugsnax. One could say she's an "anti-snaxxer".
This video on Tumblr reveals that The Triplicate Space's music is a very slowed down and slightly remixed version of "You're The Journalist". And when does the latter piece of music play? Whenever you're interviewing someone. So, the fact that this plays in the same place that you're listening to Clumby's tapes of her interview with Jamfoot suddenly begin to add up and make perfect sense!
Literally every single character was right about the Bugsnax in some way, shape or form. Let's go over the ways, shall we?
Filbo says that they taste good and make everybody happy, which is how they lure new victims to be addicted and then assimilated by them in the first place.
Wambus mentions that you need to eat them raw or else they turn to mush. And what do the Bugsnax turn out to be in the end? Parasites, which explains the eating them raw part, as they can't assimilate you if they're dead.note As explained above.
Beffica says that they're so cute she could eat them up. And that's part of what makes them so dangerous; them being seemingly innocuous sources of food. Gramble says something similar, despite him being a vegan.
Wiggle mentions that the Bugsnax are "forbidden fruits", which, with the revelation that they're actually dangerous, mind-altering parasites, turns out to be the case.
Triffany says that whatever civilizations formed on Snaktooth have risen and fallen but the Bugsnax stay, making them "walking records of history". In this case, that's a literal statement, because the Bugsnax assimilate whoever eats them into the island to be reborn as Bugsnax!
Cromdo that they're delicious and irresistible, which again is what makes them so dangerous.
Chandlo mentions that they're a "primal kind of strong" and "own [Snaktooth island]". And it eventually turns out that the entire island is literally made of them.
Snorpy tells you that he believes they're a synthetic kind of lifeform designed to "beguile our tastebuds". And that's how they lure you in.
Shelda calls them "toxin", and she's right in the sense of "ultimately unhealthy".
Floofty calls you — the journalist — an "emotional parasite", which is what they — the Bugsnax — are! They prey on your emotional and physical weaknesses because they're literal parasites!
In her second interview, Eggabell says that they can make her feel like "nothing else in the world matters" for a little while. And that's how they get you addicted to them.
Calling you an emotional parasite -> Snorpy's emotions about the unethical things that the government was planning to do to their invention drove him to whistleblow on them, getting both him and Floofty in trouble.
Being an idiot in their eyes? -> Floofty seeing Snorpy and the government as idiots for ruining their career, and ruining their scientific projects that could have changed the world.
Unethical experiments on themselves and others -> The whole thing started because Snorpy had a crisis over ethics.
This crosses over with Fridge Horror. There are several different locations throughout Snaktooth Island in which the Snaxsquatch appears. In Scorched Gorge by Cromdo's windmills, in the small wooded area to the right of the entrance of Sugarpine Woods from Snaxburg, etc. And one possible location for it to appear is in the Frosted Peak region on a small alcove overlooking the area where an igloo and the giant door you need to open resides. In addition to the door and the igloo, Eggabell is often shown standing there as she tries to figure out how to open the door and is more than likely staying inside the aforementioned igloo. And since the Snaxsquatch is eventually revealed to be a construct of Lizbert's in an attempt to watch over everyone and communicate with them about the dangers of the Bugsnax, it wouldn't be too hard to come to the conclusion that whenever the Snaxsquatch spawns in that area in the Frosted Peak, it means that Lizbert is watching over Eggabell. This is quite the bittersweet moment in that it clearly shows how much Liz cares about her girlfriend to keep an eye on her, but at the same time, Eggabell has no idea about this since she never mentions the Snaxsquatch. And Liz has no way of communicating with her about what's happened. She can't tell her that she survived, she can't tell her that the Bugsnax are parasites, she can't tell her that she loves her… nothing. It's practically an And I Must Scream moment!
Fridge Horror
The sheer amount of backstory on the island, the many disappearances, the abundance of Bugsnax and the horrifying appearance of the inside of Snaktooth Island… Just how many people died? It's possible this is why even Triffany's grandma was not even… found. Yikes.
Even worse, once you locate The Triplicate Space and listen to Alegander Jamfoot's recordings, he mentions Bronica "had gone to a place that no one should follow". Could this imply a Fate Worse than Death?
Accompanied by a bit of Fridge Sadness, it's revealed by the Golden Ending and the Lizbert cutscene that Grumpuses CAN resist the Bugsnax with enough Heroic Willpower and/or Character Development, and there are many signs that Grumpuses have been on the island before, yet this expedition is the first one that has been confirmed to have any survivors. This group may very well be the first/only ones that actually learned to seek genuine improvement and growth as opposed to attempting to fill their personal voids with Bugsnax. It's possible all the others doubled down on Bugsnax instead when their problems weren't getting solved.
It's a good thing that Snorpy stopped Floofty from cutting off their head when he did. Even on the off chance their head would regenerate, from what the ending shows of their leg, that probably wouldn't have lasted long once the effects of the Snax worked through their system.
And that's assuming the cranial regeneration even works the way Floofty was banking on. "Regenerating" a snak head, with a snak brain, was at least as likely to result in Floofty immediately undergoing complete snakification and assimilation into Snaktooth Island, or worse.
If Floofty's whole body regenerates from their head, and they get a snak torso and limbs? The ending shows that they lost their leg for good because they cut it off, so they would've been left as a head with no lungs once the snak matter atrophied!
During the spooky campfire stories, Beffica points out that some of the bones to be found on the island have teeth marks on them. This leads to a short discussion about Grumpuses becoming cannibals. After The Reveal near the end of the game, it makes sudden, horrifying sense why they'd do so on an island seemingly full of food: if they somehow learned of the true nature of Snaktooth Island, some Grumpuses probably tried to refrain from eating the Bugsnax so as not to be assimilated, only to instead start eating each other since there was nothing else to eat.
This could also explain the fossilized snak matter found near where the stomachs of some of the skeletons Triffany unearthed would have been: they're snakified Grumpus limbs, cut off to keep the "donor" alive longer and stretch the food supply out.
The most obvious, undeniable way the cannibal Grumpuses could've found out about Bugsnax' true nature? Watching one of their own literally fall apart right in front of them! And since they likely spent a great deal of time together, that means watching someone they care for — a sibling, a spouse, a parent, a child, or even just a friend — die right in front of them.
Think about it. A cluster of elements of a system turning more and more other elements into more of itself, growing and spreading without any regard for the survival of the system. We have a word for that sort of thing, and it's not a pretty one.
Another point of horror to consider is in regards to how it all started and how long it took to get there. As this commenter on the video for the Bugsnax OST "Yes, Save Friends!" so eloquently put it:
2Ali Cat7: The film to invite you was made the day liz and the gang first arrived at Snaktooth. If it is true that they have been on that island for a year by the time you get there, then that means it took a year for that film to get from Snaktooth, to the mainland where you are. You get the film then leave for Snaktooth and to get from the mainland back to Snaktooth — two weeks. And at end of the game when you use the same boat to get from Snaktooth back to the mainland — less than a day. It went from a one year distance to a two week distance then to a one day distance... That island is moving closer and closer to the mainland over time.
Wambus calling it "An Island-sized pest" might not be too far off.
The time difference can be explained by modes of travel; the group came on a non-flying boat and probably didn't send the film out immediately after it was finished, since they were still building a village. We also don't know if the beach they landed on is anywhere near the city where the journalist lives. But we will admit the island does seem too close to the coast to be unexplored for so long.
Considering what we're shown with Eggabell, what with her depression and all, as well as her saying things like "you'd be fine if I wasn't around" and "Liz saved me, like she always does", it wouldn't be too far-fetched to come to the conclusion that she's suicidal.
video on Tumblr reveals that The Triplicate Space's music is a very slowed down and slightly remixed version of "You're The Journalist".