When each character makes his trademark gesture, such as Felix' triumphant laugh, the exact same footage (with voice and sound effects), inserted onto a different background, is often reused from episode to episode to save money. See more
Felix the cat, / The wonderful, wonderful cat. / Whenever he gets in a fix / He reaches into his bag of tricks. / Felix the cat, / The wonderful, wonderful cat. / You'll laugh so much your sides will ache. / Your heart will go pit-a-pat, / Watching Felix the wonderful cat.