If you remember your Beowulf, Grendel was the big, bad monster who ate Danes for breakfast, lunch, dinner and snacks and terrorized good King Hrothgar’s realm until the mythic Scandinavian warrior Beowulf himself told him where to get off. Well, it’s taken some 1,000 years, but Grendel is finally having his say. In the world premiere of the opera bearing his name, the outcast fiend is actually “a passionate thinker trapped in the body of a beast, who struggles with his own existential conflicts and observations about humanity.” The creation of Academy Award–winning composer Elliot Goldenthal, with a libretto by Tony Award–winning director Julie Taymor and J.D. McClatchy based on John Gardner’s novel, Grendel is, in the words of Placido Domingo, “the most ambitious and complex opera ever staged by L.A. Opera.” The malfunction of the production’s huge, pivoting platform caused its opening (originally scheduled for May 27) to be moved back to June 8. Conducted by Steven Sloane and Lionel Friend, Grendel numbers in its cast Eric Owens as Grendel, Richard Croft as the Shaper, Charles Robert Austin and Raymond Aceto alternating as King Hrothgar, Denyce Graves as the Dragon, and dancer Desmond Richardson as Beowulf. There are also a few “Dragonettes” to make things even more lively. At the Music Center, Dorothy Chandler Pavilion, 135 N. Grand Ave., dwntwn.; preview Thurs., June 8, 7:30 p.m.; continues Sun., June 11, 2 p.m. & Wed., June 14, 7:30 p.m.; thru June 17; $30-$205. (213) 972-8001 or www.laopera.com.