Group Writing

[zombiekiller]

Years ago I read a book in which the author gave a basic premise to three other writers so that the four of them could each write a story using that premise. The result was four wildly different stories ranging in genre from sci-fi to murder mystery. I'd be interested in starting something like that here for any of you writers out there. I'll start by stating a premise and anyone out there who might be so inclined (inspired?) can respond with a story they've written about it. Next time, one of you can propose a new premise and so on and so forth.
Here's my premise: There is a planet where there are killers who kill every day one thing at a time. They can't actually snuff out the life force, only mortally wound. They must wait until the thing dies to wound again. People give them roaches and other slow dying things, but eventually, people will die. Who should live? Who should die? They won't stop until all life is extinguished.
I know that this is a cheesy premise, but it might get my creative juices flowing so that I can flex my writing muscles. Hopefully some of you out there will write in with some stories and with some story ideas. I think this will be a fun way to develop concepts and characters, find my voice, etc. Also, I think it will be a blast to read what you all come up with! Have fun!