Daily Mission

After clearing floor 100, Daily missions become available to complete for rewards; each day has it's own special infected, each more powerful than the last, starting with the weakest of them on Monday. Super Zombies in the daily mission glow red, as apposed to the green glow of the normal Super Zombies, to better tell them apart. Every mission requires you to kill 10 of each special zombie and the reward for each day gets better and better, to compensate for the zombies growing stronger.
 * Daily Mission