- The entire premise. Mutant zombie fish robot things take over the entire. Friggin. World.
- In classic Ito-style, the effects of the infection are drawn in uncomfortable amounts of detail. Every belch, boil, drop of sweat and set of milky, dead and staring eyes is there for you to see.
- Are you afraid of sharks? Well you're going to love this giant zombie shark!◊ Even better, it can walk on land!
- What happens to Tadashi in the OVA.◊
- The first part of Gyo is actually very funny (you wouldn't expect it from Junji Ito, but there you have it), what with Kaori being chased around by a fish in a floating balloon, not to mention the Crazy Awesome shark tank, but then the infection spreads to humans, and suddenly the manga isn't funny. It's not funny at all. One image stands out: multiple giant Spider Tanks, covered by bloated, infected near-corpses (doomed to serve as power sources for the tanks), advancing slowly but relentlessly through the Fog of Doom, gathering up new "power sources" to replace the ones who have finally rotted away.
- While Tadashi mentions in the second part that the walking fish have rotted away, by the end of the second volume more and more of them are starting to come back. The infection has clearly spread across the planet, and now the infected are converging on Japan...
- The very last image of the manga showed the main character sitting down next to the charred skeletal corpse of his girlfriend, and sadly musing that at least she's finally free from the stench of rotting corpses, which she hated in life.
- Lets not forget the fact that the gas itself is being directed by an otherworldly force, implied to be the ghosts of those killed by the experiments of Unit 731 and similar units throughout Southeast Asia in the Second Sino-Japanese War and WW2. This, incidentally, makes Gyo one of the few manga to even mention Japan's wartime atrocities.
- Oh, and the Citrous Circus. Christ on a bike, the Citrous Circus. Never mind that there's a deforming, rapidly-spreading gas-based apocalypse happening all around us, but in the midst of it a hideous, deranged carnival performed by the infected is just... well, happening. Now ask yourself, what is the worst part about this? Is it the gathering of bloated, dour-faced infected numbly performing discordant instruments while the Spider Tank-bound "power sources" perform circus tricks? Is it the sad collection of people, circus animals and others trapped in some terrible cycle of disturbing jubilance? Or maybe it's the circus-master himself - seemingly uninfected, but driven insane by the knowledge that there is an otherworldly force directing the gas, and worse, has discovered whimsical applications for it. Behold - the application of fire to the mixture.
Nightmare Fuel / Gyo