Megadeth performed two songs - new single "Public Enemy No. 1" and "Symphony of Destruction" - on Jimmy Kimmel Live on Halloween night, leading up to yesterday's release of their brand-new studio album TH1RT3EN. They also met Pee-Wee Herman, as you can see above. Now, the band has posted these backstage videos of bassist David Ellefson getting made up, and of Ellefson and drummer Shawn Drover in full costume, sending a message out to fans before performing. Check 'em out!

And now, in case you missed them on TV or yesterday, here are their two musical performances:

Megadeth's TH1RT3EN is in stores now; get it on iTunes or at your local Best Buy! Exclusively at select independent record stores, pick up TH1RT3EN and get a limited edition collector's card featuring facts from the band and exclusive imagery.  Collect them all at