Dave Mustaine was recently seen opening up for his old band Metallica during the spate of Big 4 concerts that took place. It was back to business as usual for Megadeth last night, where they returned to focusing on the promo duties for the just-released Thirteen by playing “Public Enemy No. 1” from it on Jimmy Kimmel Live. Megadeth might not be the first group you think of for having a sense of humor, but here the band members dressed up for Halloween, with Mustaine making a surprisingly convincing version of Frankenstein’s monster. The band also performed “Symphony of Destruction,” check both tracks out below.