A flying sheep's head hit an Oslo, Norway concertgoer and fractured his skull at a concert of metal band Mayhem. The band, part of Norway's death metal music scene, was carving up a dead sheep as part of its stage act when the animal's head flew off lead singer Maniac's knife and struck 25-year-old Per Kristian Hagen. ``My relationship to sheep is a bit ambivalent now. I like them, but not when they come flying through the air,'' Hagen told The Associated Press Monday from his hospital room. He is expected to recover. Hagen filed involuntary assault and battery charges against the band. The charges carry a maximum sentence of six months in prison.