Hm....Depends on what KIND of zombie. If they turned into one of those slow boring classic zombies, I'd lock him/her in the closet, then find the cure. If it was a fast type of zombie, like on Left 4 Dead or Zombieland, I'd probably try to shoot them, fail, and become a zombie myself. ^^;
WWYD if you could magically transform into any ONE character? From anything.