Yako looked at her friends who are studying like crazy for the exams, ate an oyster, and then finally realized what was going on. She then asked Kanae to help her with a reward of 3 fried oyster. Kanae, of course, not having any of that.
In the same arc, Akane tried to cheer Yako up with tea and fish's eye ball. Normal people would freak out at something like that but Yako just mildly surprised and ate it anyway (she even commented that it was tasty).
Godai cried and screamed that he'd already finished 6 years of compulsory education before running away (There are 9 years, but let's not tell him that)
The Valentine chapters in which Yako prepared the chocolate which look like a pot of witchcraft and big bags of chocolate behind her. She tasted one piece (bigger than a tennis ball) then use a 5-times-larger piece to make a double chocolate fondue. After finished cooking, her 20 kilograms of chocolate has reduced to 7 pieces of candy.
In the same chapter, Neuro sabotages the chocolates Yako made with Demon World Mud.
Yako throws her gift to Godai like it was some kind of bomb or garbage.
After the chase, Godai's new car has been reduced to a single logo badge.
When Yako was researching about Eisuke, Usui offered his help by telling her that she could order any food she want. Few minutes later, he realized his mistake and ran back to stop her. He was way too late.
The Government discussing about whether they should give up the supercomputer or not, a member declare that he can consult with his friends to stop this. Seconds laters, the predictable outcomehappened.
During their trip to the gas poision infected area, people's reaction when they recognized Yako (right after they talked about the nine-tailed fox) is this:
"Uwwa, Yako Katsuragi is here!"
"Quickly! Offer her some food!" *Bring out food*
"They say she'll even eat people if she's hungry!"
After defeating DR., Neuro came home planning to vent the rest of his anger on Yako. When he arrived, he smiled so sweetly and Yako immediately knew what's he going to do with her. In the next page, the two of them chatting so normally while Yako trying to escape and Neuro preparing to throw chain around her. When he finally get her, Yako looked at the tools he'd thrown on the ground and concluded that she's not going to comeback alive tonight.
Even when he cannot move, Neuro is still deadly.
The whole fishing contest and Neuro's plan to keep Yako busy by letting others feed their fishes to her. She knew it was a trap and yet still fell for it.
Yako *chomping down on her bowl*: "Uh-oh, it's delicious but uh-oh."
In the anime; Neuro discovered the killer...however Yako wasn't there. Cue him pulling out his cell phone to get her to do the entire speech. Afterwords, we see an exasperated Yako handing Godai's cell-phone back to him while they were driving elsewhere in a car.