Meow Mix
JayleneSlide
"There was a moth. I saved you from it "
There were a couple books I read long ago, one of which I think was "Catwatching" by Desmond Morris. I can't recall the other one. Both books indicated the chittering was a frustration sound.
By executive order, I decree that humans are, effective immediately, forbidden to ever allow the lap to disappear, ever stop petting or playing with me, or ever leave to go to work. Additionally, I now have Presidential immunity to sleep between JayleneSlide's legs all night, and hugs and kisses must be delivered to my head at every meal time.
Not a game per se, "Hugs and Kisses." My cat had to go on a special diet for a few months. I put down her morning food, and she balked at the change. I was leaving for work and feeling like I should stick with her for the day. So I grabbed her, gave her a kiss on the head and, in a silly voice, said "Hugs and kisses, HUGS AND KISSES!" I put her down and she ate her food.
From that point forward, she wouldn't eat her food unless I did the hugs and kisses thing. It had to be the full dance, the same voice, or she wouldn't eat.
That looks a lot like fugu. But I'm sure that shokunin prepared it properly!
When I still had kitties (and a house), I bought a litter box with a lid. I then fashioned a vent hose with a 120mm 12V PCM fan running at low RPM. The hose went through the ceiling in a closet and exhausted out an attic vent. Zero cat box smell and no noise. While my exact implementation isn't available to everyone (like in apartments), the basics can be adapted to almost any situation.
Monterey sea lemon, Hood Canal WA USA

Ask and ye shall receive! Giant nudibranch, Sinclair Inlet, Bremerton WA USA

These nudis are very common on the docks where I moor my boat. This picture has the saturation punched up, but still fails to convey just how trippy they, and most other nudibranchs, look in person. The iridescence in the rhinophores and cerata is something that can be tricky to capture with imaging. Here is a different angle of the same species.

The toxicity is in the dose. If you're actually allergic to your cat, it could be a seasonal change in his grooming regimen resulting in more saliva on his fur, which means more allergen proteins in the dander.
Another possibility: seasonal change has resulted in something blooming to which you're mildly allergic. The combination of things might have tipped you over the edge of allergic response.
There are a ton of factors that could be in play, and only an allergist can tell you for sure what's going on.