I hate to break this to you, but that's a lot of synonyms. Manga is just a specific format of comics, the way anime is just a specific style of cartoon.

That being said, a lot of what makes zombies a good horror monster is their numbers combined with the appearance. One zombie is gross and a little scary. A swarm of them is terrifying and disturbing in a much bigger way.

You can't draw enough detail into a panel that will carry the same feeling as you can when drawing for a bigger screen size. And, because of movement, you can convey the danger of that mob better. A static image of a horde of zombies hits different than a swarming mass of rotting hunger.

I'm not knocking the ability of a good artist to convey movement, or to bring a sense of horror to that kind of scene, they can. I'm just saying that when you're immersed in the moment, reading or watching, the impact of seeing pustulent bodies rubbing against each other in a drive to devour something alive is just more.

Now, what you can get in static media is up close horror. A good artist can take a moment and give it depth and emotion that is harder to achieve with animation. The more "zoomed in" the image is, the more a still image is going to be able to give the reader time to soak in the sheer terror of what fictional zombies represent.

I would argue that live action is superior to animated in most ways though. Assuming a halfway decent FX effort and some good camera work, the impact of seeing something that's more realistic can't be denied.