"Zombies are like... a really bad cold. Except if you get this cold, it makes you look like a walking corpse and you want to eat people. And if you get bit, you're probably going to catch the zombie cold, okay?"
George didn't try to explain the undead aspect of zombies. The jeanie was a little slow and the reaper was more concerned with saving her life. No one deserved to become undead. George knew from experience it wasn't a particularly fun affliction.
"So, we need to find somewhere safe. Somewhere you can hide or something."