You immediately begin to have all of your feelings rush back! A blinding pain
and searing heat washes over you as you regain the conscious energies of life.
Within moments your spirit and your body seal together and body repairs itself
to once again act as a vessel for life. In a last, brief moment, you gasp for air
and realize that you have been given another chance!
Something feels... wrong, though. You suddenly lose your wits and your muscles
begin to bulge. Your body turns a sickly green color and you begin to haunch
forward slightly.

Here's what becoming a zombie means:

+15 Strength
+10 Stamina
-15 Agility
-15 Intelligence
-10 Wisdom
-10 Coordination

I bet there are some effects beyond the stat change, but I am unclear on specifics.