The FLOOD

"The parasite is not to be trifled with"

So I've decided to post a bit of warning to flooders. This comes from the game Halo, where you play a green armored guy shooting aliens, and here's where a totally gruesome type of enemies are introduced into the game. The Flood are a sort of parasitic organism.

In this video, you have just played through a few relatively empty maps where the marines you're searching for have all gone missing, and it is too quiet to be good. Then you chance upon a door and find a recording. The 'Covenant' refer to a group of several species of aliens, while an 'Elite' is one of those speci.
For maximum effect, turn up the volume, and make sure the room is quiet and dark. (full screen would make it better, but nevermind that)



Wait.. Look behind you to check whether there's something else in the room. Here's another video. Just some soundtrack and more creeps.



Done? Now check out this picture. Basically when one of those small creatures implant themselves into a human, the body will be taken over and turn into this. More descriptions at this SITE.
EDIT: Personal record, I just scored 6 minutes 12 seconds for medium level sudoku!