After defeating the hag I went to Marianna and tried to resurrect her husband Conner - obviously he turns out to be a corpse and i decide to keep him as my little pet lol, the bug is it seems i can summon him as many times as I want
I stopped trying after 3 or 4 at a time but i can imagine that aside from the summons being restricted by a time limit i can have a horde of zombies like this.