The Laughing Corpse (Anita Blake Vampire Hunter #2) 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.