Bukkit

Creepersday - Randomly, be invaded by creepers.
Version: 1.7 - [ Présentation française du plugin : sur Bukkit.fr ]

Sometimes, your Minecraft worlds are too quiet... With Creepersday, this is over :)
A special day happens randomly: Lots of creepers (and powered ones) will spawn around you…

Can you survive? We'll see!

Highly configurable, multi-world support, … Creepersday is definitively funnier with friends:
Throw them eggs (which normally make appear chicken, but during the Creepersday…)
and try to get the highest score at the end.

Breaking news: Now you can control Creepersday... from your iPhone ! :-)
You don't believe me? >>> click here <<< (start at 4:05)

Quick review by puffnuget:

Documentation: English - Français
Get the source code: On GitHub

If you want help me to pay my internet connexion, you can

Usage:
Simply copy the jar file into your plugins directory, then start your server.
Default config files and documentation (EN and FR) will be copied into plugins/Creepersday.

You can edit settings then run the command /creepersday-reload-config to use new values.
/creepersday start/stop allow you to force starting/stopping a creepersday.

Features:

• Highly configurable
  
• Settings can be change by world
  
• Support several language (FR and EN by default)
  
• Bonus items can be given to players on start / during / after the day
  
• Stats with score of best players are displayed at the end
  
• Settings can be modified without restarting the server
  
• Included documentation (FR and EN)
  
• ...
  

Permissions:

• creepersday.*: Gives access to all creepers'day commands
  
• creepersday.force: Force starting/stopping a creepers' day
  
• creepersday.reload: Update plugin config from files