There's no shortage of horrifying ways for anime characters to meet their end. One of the most horrifying is being eaten alive - a trope that you'll find in only the most gruesome anime.
Some anime characters who were eaten alive perish in astonishingly horrible ways - that's certainly the case for the townspeople who are taken out by man-eating rabbits in Blood-C, as well as all the people who lose their lives to Titans in Attack on Titan.
There are a few characters who actually survived being devoured. Filo from Rising of the Shield Hero is swallowed by a dragon, but she bursts out of it by turning the tables and eating the dragon instead. There's also Sakura Minamoto, a zombie who is eaten by a boar, but makes it through because she was never alive to begin with. These examples are funny because things turn out okay, but just about everything else on this list is straight up bone-chilling.
Even if you're not familiar with Blood-C, you've probably at least seen pictures of the Bunny Elder Bairn. This rabbitlike monster duplicates itself by the hundreds, then sets about devouring an entire town full of people. Whether it's popping civilians into their mouths like popcorn or gathering a group of them into a sac made from its own flesh, then turning that flesh into a blender that absolutely eviscerates everyone inside, this is one of the most gruesome scenes in anime history.
Saya, the series protaognist, is eventually able to put a stop to the horror by taking out the original, but not before thousands of people lose their lives.
While Carla Jaeger is far from the only person to be eaten alive during Attack on Titan, she's certainly one of the most memorable. Carla is Eren Jaeger's mother, and her passing was the catalyst that drove him to want to destroy Titans with the passion he exhibits throughout the series. Carla is a devoured by a Titan who entered Zhiganshina through a hole in the wall, while her son watches helplessly. It's one of the most chilling moments of the series, and a preview of what is to come.
In one of the more gruesome moments in an anime that routinely delivers disturbing scenes, Scheele is devoured by Seryuu Ubiquitous' pet dog, Koro. This happens when Scheele is taking on Seryuu and Mine is up against Koro. Koro transforms and lifts Mine in its giant paw, prompting Scheele to drop her own conflict to lop off the dog's arm. While this allows Mine to escape alive, it also gives Seryu the opportunity to shoot Scheele in the back. As she loses consciousness, the dog devours her.
The biggest threat to the cast of The Promised Neverland is being consumed by the demons that are raising them as livestock. Few characters have actually been eaten yet, and when it has happened, it's typically a cut-to-black occurance that doesn't force you to witness the blood and guts. But that type understatement doesn't make it any less upsetting when Conny, a little girl who thinks she's going to go live with friendly new foster parents, is gobbled up by a demon while her horrified friends look on. All that's left of Conny is a stuffed bunny rabbit.