Step into the Slave Pit as masters of destruction Gwar headline the third annual Gwar-B-Q, a day-long festival of food, loud music and all-around mayhem. Although the event was plagued with last-minute permit issues and location changes last year, Gwar frontman Oderus Urungus promises that all the paperwork is in order. The big event every year is the Spew-O-Lympics, where fans compete against each other in a drunk and disgusting display of skills, executing a rope swing, a pillow launch and an egg race while being showered with foul fluids. Two stages will feature performances by the Casualties, Strike Anywhere, Ghoul, Valient Thorr, Murderess, the Burial, Lionize, Occultist, Lost Tribe, Highness, Antietam 1862, Mutwawa, Black Naked Wings and, of course, Gwar in all its glory, including the return of the Sexecutioner to its live show for the first time in 12 years. The Gwar-B-Q takes place at Hadad’s Lake on Saturday, Aug. 18, from 11 a.m. to 7 p.m. $25-$35. gwarbq.com.