killjoys are characters from a concept album; comic book-style heroes fighting the man. Watch the video if you're curious. :)
http://www.mychemicalromance.com/media/videos/my-chemical-romance-na-na-na-official-video

What's a Killjoy?

totally! I'm wearing my MCR concert T-shirt right now. :)

omg u like slender man too? i love his hot bod! lol

An MCR fan i'm sensing?? ;D

A killjoy doll maker would be awesome!