Legendary thrashers Anthrax kicked off the Rockstar Energy Drink Mayhem Festival Saturday without longtime drummer Charlie Benante, who is recovering from a recent hand injury. Filling in for Benante is Shadows Fall drummer Jason Bittner, who also filled in when Benante missed time for the birth of his first child in 2006 and again earlier this year when Benante and Anthrax bassist Frank Bello (who is Benante's nephew) missed time to be with Benante's mother who was suffering from a terminal illness. Check out some fan-filmed footage of the Rockstar Mayhem Fest kickoff below.