The zombie marine is complete, so even though ammo is still scarce, it should now be possible to at least finish most maps by rationing resources and hunting down and scavenging supplies from zombie marines.
Two variants in the spoiler, one with the zombieman crew cut, and one baldy like the shotgun guy.
I'm translating them with ["112:120=128:143", "121:127=236:239"] for the zombieman and ["112:120=104:111", "121:127=5:8"] for the shotgunner, but you can obviously do whatever you want with these. No XDeaths because I'm just reusing the vanilla ones, and the attacks only have 4 rotations because I got tired of this sheet, but there is an alt death because variety is fun!
Credit to Solmyr and Metal_Spaghetti for the melee marines. Probably OSJCLatford as well? I don't remember for sure, but I've been tinkering with his possessed sprites a lot, as you can see, so there's probably some of them in there too.