Some quick TF in Marvel Zombies 4.....and as far as I can tell, it's evil conversion, not zombie conversion.
Jennifer Kale is a magic-using hippie chick. She's on the cover here, the blonde on the bottom. During the course of the miniseries she makes a deal with the demon Dormammu, becoming the creature you see in panel two. Sadly there is not much process, besides her temptation earlier in Issue 3. You just get a before & after.