Complex sentence: Badgasarian also voices Alvin Seville, the leader of his brothers and the oldest chipmunk who is known for his arrogance and egotism; and Simon Seville, the middle, who is highly intelligent and extremely practical, with a very dry sense of humor.
Split into simpler sentences: Badgasarian also voices Alvin Seville, the leader of his brothers and the oldest chipmunk. He is known for his arrogance and egotism, and Simon Seville, the middle, is highly intelligent and extremely practical, with a very dry sense of humor.