Hmmm … “Eaters-of-the-dead” … that wouldn’t be so bad. But all I can think of is, (PLEASE!! forgive me, Deutsch speakers!) “Todenessenern”?
To me (, a native German speaker,) “Totenesser”(would be “correct”, I guess) sounds too flat, it does not roll off the tongue easily – I cannot exactly put the finger on it, but there is something wrong with it.
“Leichenschmauser” would be kind of funny (Leichenschmaus = funeral feast), but it is too soft for a deadly creature and too long and not catchy enough.
“Kehrer”(= sweeper) would be fitting, since they do clean the battlefields; it is catchy. But probably no good name for a creature.
I’d deem “(sich) laben” a good, german word to describe the ex-ghouls’ main characteristic in one word, since it means “to revitalize/brace oneself by eating/drinking”. But I don’t know what would be the corresponding noun and, after some research, I think there is none.
I guess, it would be “Laber”, “Labener” or “Labner” – they all do not sound like good names for a beastly creature.
But a “Lab” could be a creature (it reminds me much of https://en.wikipedia.org/wiki/Alp_(folklore) ), though this is already the german word for “rennet”.
The least form could be called “Labling” (,where the “ling” indicates that it is a little/lesser, not (very) dangerous creature like a “Frischling” for example), the middle form “Lab”
and the highest form “Laberdan” (, though this is actually already a german expression for “pickeld cod”; I think it is a really fitting name, especially for the fatso-ex-ghouls, with a good sound to it in general and it also has a dangerous vibe to it, at least for me (as a (native) German (speaker))).