Sorry there is no Biography!
While filming the scene in Poltergeist where the clown doll comes alive and tries to pull him under his bed, Oliver went through a near-death experience. When the puppet arms wrap themselves around his neck, he was unable to breath and began choking. Steven Spielberg thought he was acting (he even yelled "Keep going! You're doing great!"). It was not until Spielberg saw his face turn blue that he realized the young actor was in trouble. Spielberg ran over and pulled the puppet off, saving Oliver's life.