Wikipedia:
Zombies, Oh my god
Urban Dictionary:
zOMG is a variant of the all-too-popular acronym “OMG”, meaning “Oh My God”.
The “z” was originally a mistake while attempting to hit the shift key with the left hand, and type “OMG”
Also used in all-caps, ‘ZOMG’ is generally used in a sarcastic manner, more often than not a humiliating fasion. It is also used as a device for stating the obvious.
“zOMG! you r teh winz!!one!!eleven!”
Atheists believe in the Goddess Athe, who is wise and powerful beyond measure. They are some of the most religious people in the world.