Scary-looking aliens who eat foods the viewing audience would find disgusting appear quite a bit in Science Fiction. Klingons, for example, eat gagh (live serpent worms), racht (live worms), and Rokeg blood pie. Scary aliens, disgusting food.
Now, the aliens in War Of The Worlds were famously defeated by simple Earth pathogens. But what I wonder is this: Are there scary-looking aliens who would be unable to eat humans’ food? Imagine a Klingon or a Predator type who wolfs down a bowl of pho with sliced jalapeño or Serrano chiles in it. He either can’t take the heat, or perhaps he goes into immediate anaphylaxis. Or maybe their eyes burn when they are in the proximity of someone who has just eaten biscuits and gravy with lots of black pepper. You know how you shouldn’t rub your eyes after slicing peppers? Maybe the touch of someone who has handled peppers cause their tough, scary-looking skin to blister.
But what I’m thinking of is something that can have harmful or painful effects on humans (such as various peppers) that many humans eat and enjoy. Not something ‘universal’ like water, or salt killing a Slug Creature.
To completely hijack the thread in the opposite direction, does my memory fail me, or did Worf, in TNG, upon encountering prune juice for the first time, declare:
My favorite scene – in fact, the only scene I remember – in the novel Planet X (an authorized ST:TNG/X-Men crossover) is where Wolverine visits Ten Forward and, complaining about the synthetic alcohol being served, demands something strong, something that Worf would drink. Guinan responded, “Oh, you want a warrior’s drink.”
A lot of people enjoy the flavors of acids (sour) and alkali (bitter), which can be unpleasant (and even corrosive) in high concentrations. Can’t recall it ever being used in a science fiction story, though.
In Larry Niven’s Ringworld novels, there’s an alien race that’s disgusted by humans’ fondness for spoiled foods – like cheese, or anything fermented – but as they never did eat any of it, we never found out what, if any, effects it would have on them.
Not quite what you’re looking for but I recall a scene in ‘Children of God’ by Mary Doria Russell where the herbivorous humanoid (well bipedal anyway) alien species one of the human characters is living among is shocked and somewhat frightened when she accidently cuts her hand and starts sucking her own blood from the wound.
That’s what I’m looking for. Earlier, thinking about this thread, I thought of things like citrus fruits, tomatoes, and other acidic foods that a scary-looking alien might suffer a severe reaction or possibly death from consuming, or whose skin happens to be sensitive to acids.
In Scott Sigler’s Galactic Football League series, the Alien Ki, who usually play as linebackers, have eating habits that most humans find disgusting. This plays a significant role in at least one book.
Conversely, at one point the Ki are invited to attend a typical human BBQ dinner, where we discover that hamburgers are so vile, the Ki immediately vomit after their human host insists that they at least try eating human food.
Wasn’t there more too, like they couldn’t digest cooked meat or processed dairy? There was a running gag about the Newcomers eating various raw animal parts and organs. I distinctly remember Cathy getting sick when she tried to eat some lasagna.
They weren’t aliens, the hot dogged mouthed monsters from The Horror of Party Beach were melted by sodium. So, no Campbell’s Soup for them, I guess. Unless it’s from the “Heart Healthy” line. And they can have all of that, as far as I’m concerned.
They are killed by salt water, though, and unlike Signs or War of the Worlds, it’s entirely possible they are a non-sentient, accidental alien colonization rather than a intelligent species working intentionally. You don’t blame a dandelion seed for ending up somewhere inhospitable.
In Harry Turtledove’s Worldwar series (aliens invade during WWII) one serious problem the aliens run in to is that an Earth substance turns out to be highly addictive. That substance is ginger. Consuming ginger has a strong narcotic effect in males and it also makes females fertile and release hormones. In a species that has very specific mating seasons and no sex drive in between this becomes a crisis for the whole species.
Dunno if they count as “scary,” but Turians from the Mass Effect series evolved to gain nutrition from dextro-amino acids, and can get seriously ill or die if they consume human food. Same goes for the Quarians, but they aren’t as dangerous-looking as the Turians.