The Laughing Corpse by Laurell K. Hamilton
'The older the zombie, the bigger the death needed to raise it.'
After a few centuries, the only death 'big enough' is a human sacrifice.
I know because I'm an animator. My name is Anita Blake. Working for Animators, Inc. is just a job - like selling insurance. But all the money in the world wasn't enough for me to take on the particular job Harold Gaynor was offering. Somebody else did, though - a rogue animator.
Now he's not just raising the dead... he's raising Hell. And it's up to me to stop it.