Complex sentence: His first credit was for "Sinkin'In The Bathtub", released May 1930 and animated by Isadore Freeling; his last credit for Warner Bros. was in 1933 with "Bosko's Picture Show".
Split into simpler sentences: His first credit was for "Sinkin'In The Bathtub", released May 1930 and animated by Isadore Freeling. His last credit for Warner Brothers was in 1933 with "Bosko's Picture Show".