A cat gets eaten by a monster but it does not show it actually happening in the comic but it does get pretty graphic in the Netflix show. It's in episode 1 about 25 minutes or so in.
In the 2020 Netflix series the cat is eaten in the first episode. It’s pretty gruesome as you see it’s head roll into view before the girl eating it snatches it back out of view. It’s 26 minutes in and lasts maybe 10-15 seconds.
I don't think this is included in the show, but in chapter 115 of the comic there is a man who tries to rape a woman. He was also a bit sexually creepy in a couple of the chapters before that, but it's the worst in chapter 115.
In the 2020 netflix series in ep1 a character coughs up and forcefully spits out noodles. Its very sudden.
The scene is right after a character puts a cigarette in anothers mouth.