An Advanced Creature Profile by Vincent Groth.   

The Ghouls are risen corpses, often mutilated, with extended claws and fangs. Ghouls can form in three ways from a failed siring where the victim dies before its complete, animating the corpse of a cannibal, or dying from a bite from a ghoul. Older Ghouls bodies mend, their claws become retractable, and they gain a semblance of life making them one of the few undead that can pass for the living. 

-The Talkoi are magically augmented and specialized ghouls having been bound into the shadow plane. They bleed shadow, have elongated arms, scabby leather skin, and more prominent claws and teeth.  

-The Goroul are larger, more brutish ghouls who have feed off a lot of corpses attuned to magic, the latent energy augmenting their physical powers. Their muscles grow and their dead bodies can’t accommodate causing their muscles to burst their skin pulse out displacing the fat layer. Goroul develop more gorilla like body shapes running on all fours. 

-The Ghast were once ghouls, they developed a taste for other undead absorbing the power that animates them. The amass the dark magic of their kin ghasts have no body fat, their skin shrinks of the visible muscle and bone structure of their bodies, and their eyes appear larger as their eyelids shrivel away. They are all condensed energy and strength the ground cracks beneath every step. 

The Ghouls, Talkoi, and Goroul gain intelligence as they exist and feed starting out as barely sentient and becoming fully sapient. They have vicious claws and fangs, are more agile than most undead, and their curse is carried in the saliva.  

-Talkoi can slink through shadows, have inhuman senses of smell and hearing. They can see through darkness. 

-Ghasts are even faster, stronger, and smarter than their ghoul brethren. They can acquire abilities of other undead they have fed on enough. They can feed off the negative energy of the living, killing them, and drinking in their pain and death. 

Ghouls are normally not sought out for creation as they tend to be as dangerous to the creator as those around them. They serve as terrifying forces able to reproduce through a bite. 

Ghouls, Talkoi, and Goroul all cannot enter consecrated ground, though Ghasts are strong enough to not be affected by it. Silver, Garlic, and other materials that can or are believed to combat disease seems to be a symbiotic bane to the ghoul species. Though only actual antimicrobial material can harm Ghasts.