Creator Killer: Making Tom & Jerry talk led to director/producer Phil Roman's cinematic career getting silenced for two decades; he strictly remained in television animation with The Simpsons and Garfield adaptations.
I Knew It: This film confirms the fan theory that Tom and Jerry enjoy their game of cat and mouse. Once they're homeless, they get along like a house on fire.
The Other Darrin: Technically the title characters, who previously had a slew of other voice actors the few times they'd been voiced. This was the first (and only) time Richard Kind and Dana Hill voiced Tom and Jerry respectively.
Though the film makes it seem that Tom and Jerry have never talked before the events of the film, in reality many of the early shorts feature Tom and/or Jerry speaking, with Tom speaking much more frequently than Jerry. Of course, this is assuming the shorts take place before the film.
Star-Derailing Role: This was the last movie voice actress Dana Hill was in prior to her death, and it didn't help the career of her or Richard Kind out much when they voiced the duo.
Stillborn Franchise: As far as playing in movie theaters goes, any and all Tom & Jerry movies past this one TV movies; this came not too long after The Jetsons also bombed out at the box office, and although The Flintstones fared well, Hanna-Barbera never really got on the cinema map.