"I've been far from contented lately!"
Storyline
A depressed Tom eats some cat food that makes the following promise: "Put a Purr in Pussy. Have a Contented Cat!". This miracle food puts him into a contented stupor, characterized by lots of loud purring. Jerry and Tuffy, who are being driven crazy by the incessant purring, find ways to silence it by changing Tom's mood. Tom counters by scarfing down more of the cat food and resumes purring all the more. To purr, or not to purr, becomes the question as Tom undergoes rapid fire mood swings.
Story Notes
If, during their days at MGM's animation studio, Bill Hanna and Joe Barbera had lent Tom and Jerry to Tex Avery, this is what might result. The introduction of an "outside agent" rapidly affecting a character (or characters) in counteracting ways is reminiscent of Avery's animated masterpiece "King Size Canary" (1947) https://www.imdb.com/title/tt0039535/ but with mood swings taking the place of physical growth.