Here's an example. You could take the green guy that winds up and launches itself at you, and having that mob replace the zombie. Then reskinning the green dude to look like the zombie. And all the other hostile mobs could follow a similar pattern. I make this suggestion because the mobs in this mod have some well telegraphed attacks that seem to translate well to vanilla hostile mobs and I figured it would be pretty cool if vanilla mobs could get this treatment.

I think this could better off as an addon to this mod instead of directly add it in.