Not only did Megadeth perform on "Jimmy Kimmel Live!" but they performed in full costume for Halloween! This is a very out of character move for Megadeth but I am glad to see the band having fun. Megadeth's new album "Th1rt3en" is in stores today. Seeing Dave Mustaine in a full Frankenstein costume is awesome. I give the band props for throwing it down. Check out the video.