He joined Fleischer Studio in 1931, where he worked on Betty Boop, Popeye the Sailor, and many other shorts, as well as Fleischer's two feature-length animated films. Tendlar stayed on at Famous Studios after Paramount Pictures foreclosed on Fleischer and reorganized the company into Famous Studios. Tendlar was promoted to director at Famous Studios in 1953 (he also directed a Noveltoon "A Self-Made Mongrel" in 1945).
Tendlar joined the animation studio Fleischer in 1931 and continued his work there until the company was reorganized by Paramount. He then moved to Famous Studios, where he became a director and also directed a Noveltoon called "A Self-Made Mongrel".