An unlucky dog named Dutch goes to Detectives Tom and Jerry, saying that a ruby stone he has been guarding from his great grandfather’s master pirate “Captain Wrongway Weston” is taken from a female dog named Roxy, who is also unlucky.
Toodles hires detectives Tom and Jerry to investigate and protect her against a threat to her Tuna can inheritance. They go investigate, and a mysterious and menacing figure keeps trying to hurt them.
Tom is assigned to guard his owner’s garden of crops against pests, including Jerry and a clan of harvest mice who all resemble him (albeit with different-colored bandanas).
While celebrating the holidays with Beatie and Hildie, Tom and Jerry destroy their Christmas tree and must go out to obtain a new one. In the process, they help out Santa Claus by delivering presents for Christmas.
Ginger and Rick decide to bring Tom and Spike along on their Hawaiian vacation, but on their plane flight, Jerry and Tuffy tag along as well. Tom and Spike get loose out of their cages, and before long, things go awry.
Nancy, Tom’s owner from Baby Puss (1943), brings Tom to her elementary school for show-and-tell in which she wants Tom to win the gold star for best pet.