In the comics, Negan is responsible for the deaths of multiple characters. For instance, he brutally kills Glenn and Abraham, which had a huge impact on the story.
Thanos kills a bunch of characters in the comics. He's notorious for eliminating powerful heroes and causing chaos. It's hard to list them all precisely, but it's a significant number.
In the comic book, Negan's victims include major characters like Glenn and Abraham. His actions have a huge impact on the story and the other survivors.