Complex sentence: General Skarr also makes a rather large appearance in "Billy & Mandy's Big Boogey Adventure", in the beginning of the movie he is Grim's newest job, as Skarr had accidentally killed himself.
Split into simpler sentences: General Skarr also makes a rather large appearance in "Billy & Mandy's Big Boogey Adventure". In the beginning of the movie he is Grim's newest job, as Skarr had accidentally killed himself.