Tom & Jerry (Hanna-Barbera era) S01E23 - Springtime for Thomas

It is a beautiful spring day and Jerry wants to play with Tom, but Tom is too busy, fixated with a female cat sunbathing in the yard outside. Tom stares dreamily at her for hours, until eventually approaching her and falling head over heels in love with her. As Jerry watches, a small devil (looking like Jerry, but smaller, green, and possessing a barbed tail, small horns, and pointed ears that look like Tom's) convinces Jerry to break things up between Tom and his new-found love. Jerry sends a forged letter laced with perfume to Butch, Tom's rival, whom was humming at the time "Over The Rainbow". Butch reads the letter aloud: "Dear Dream Boy, I have always admired your physique (pronounced fizz-ee-queue). Drop in for tea at 3:00. Swooningly yours, Toodles". The race is on between Butch and Tom for Toodles' affections.