A few were somehow somewhat resistant to the virus while still being infected, and while they were infected and have similar traits to the zombies, they can talk, have self-awareness, and others. However much like zombies they can't feel pain and have a major urge to eat the flesh of the living, and while many ghouls fight this urge to try and co-exist with survivors, more give in and become more dangerous than the zombies. They are also not attacked by zombies, but have to worry about the other creatures on this list, and the survivors.
These creatures are the former animals which got into the radiation, usually dogs, deer, rats, cats, bears, various bugs, raccoons, bears, ect. Still, the radiation turned them into monstrous beasts with the desire to kill and eat anything and everything in its path, often times even zombies and ghouls. These are often seen around deep forests and small towns as much of these animals did not live in major cities. Also, anthros do not count, these are feral animals.
These came from the individuals which were killed solely by the radiation rather than the infection, like falling in radiation toools, to much exposure to radiation, ect. They will often be deformed, monstrous, buffed and tall, and with a uncontrollable desire to kill anything and everything in its path. Both humans and anthro count for this.
Strange humanoid creatures which are vary slim, have very pale skin, and long sharp teeth. No one knows how they came about, some say they were a government experiment either gone wrong are severely fucked up, others say they're a mutant race. They will often seek out caves as they are cold dark and deep under ground which gives them their name, but they will often be found in other underground places, like bunkers, tunnels, subways/underground railroads, cellars, underground prisons, and even basements, anything which is dark, cold, and roomy. They will eat anything they can find, like normal animals, to zombies ghouls and survivors of any species, and even each other. Sometimes they even venture to the surface close to where they live in the middle of the night to find prey. They will often crawl, and can jump higher and further then jumpers. Another strange feature is they have no eyes, they mainly rely on sound touch and smell.
A feral mutant like reptilious creature which has the appearance similar to something you would fine in the metro system in Metro 2033. No one knows how they came to be like the Cavecrawlers, but they have four legs, very shark black claws, long thick shark teeth, and very strong and good eyes. They get the name stalkers because they will stalk prey for awhile, before attacking in groups. They will mostly living creatures like survivors of any species, normal animals of any species, and even Cavecrawlers, because they do not like dead flesh.