The biggest change is probably the fate of some characters. In the comics, certain characters survive or die differently compared to the show.
One major difference is the development of storylines. Some plot points in the show take a different direction than in the comics. Also, the character relationships evolve differently in some cases.
I think Negan is one of the biggest villains. His brutality and dominance caused a lot of chaos and suffering.
Among the villains, Alpha stands out as a major one. Her leadership of the Whisperers and her extreme methods make her a huge antagonist in the comics.
There are several. Like when a major character suddenly dies in a really unexpected way. That was a total shocker.
Beth is indeed dead in The Walking Dead comics. Her death has a significant impact on the storyline and the development of other characters.
Michonne does die in the comics. The circumstances surrounding her death were quite dramatic and had a significant impact on the story's progression. It happened during a major conflict with other characters.
Yes, Carl died in The Walking Dead comics.
Lori does die in the Walking Dead comics. Her death has a significant impact on the plot and the characters around her.
Yes, Negan dies in The Walking Dead comics.
No, Judith isn't dead in the comics as of the latest issues I know.
Gregory met his demise in the Walking Dead comics. His fate was sealed due to various plot developments and conflicts within the story.