Zombie Strength

Butters nodded. "Why zombies?" he asked.
"Huh?"
"Sorry. Changing topics. New question. Why do all these necromancer types use zombies?"
"Not all of them do," I pointed out. "Corpsetaker had called up a bunch of semicorporeal ghosts. Specters."
"But human," Butters said. "Zombies look human. Specters look human. Why not whistle up a pack of decayed rats? Or maybe semicorporeal mosquitos? Why use people?"
"Oh," I said. "It's got to do with a kind of metaphysical impression that any given creature leaves upon its death. Sort of like a footprint. Human beings leave larger footprints than most animals, which means that you can pour more energy into reanimating them."
"They make stronger goons," Butters clarified.
"Yes."
"How come Grevane had fresh corpses when he came to get me, but he attacked your house with old ones? I mean, I saw those things up close." He shivered. "Some of them must have dated back to the beginning of the twentieth century."
"Same reason they animate humans instead of animals," I said. "Older corpses leave a deeper metaphysical imprint. They're harder to call up, but once you get them here they're easier to control, stronger, more difficult to damage."
"Old corpses get you stronger undead flunkies," he said.


Dead Beat, Page 289-290