* CreatorCameo: Well, ''writer'' cameo, actually. Co-writer Glenn Ficarra played the crazy evil cat known simply as [[NoNameGiven "The Russian"]]. Incidentally, this also leads to a case of...
* FakeNationality:
** Glenn Ficarra is an American, and he provides the voice of the evil [[FakeRussian Russian-accented]] cat who breaks into the Brody home.
** Texas-born actor Charles Howerton plays an uncredited role as a German Shepherd at the Dog World HQ, who, [[RuleOfFunny appropiately enough]], has a German accent.
** Veteran voice actors Creator/BillyWest and Danny Mann, both of them American, voice some of Mr. Tinkles' ninja cats, who are, [[RunningGag once]] [[RuleOfFunny again]], Asian breeds with appropiate accents.
** [[OneSceneWonder Friedrich]], from the second movie, is a German played by an American, [[Series/SaturdayNightLive a Fred Armisen specialty]].
** Also from the sequel, Michael Beattie and [[{{Creator/JeffBennett}} Jeff Bennett]], Canadian and American-born voice actors respectively, provide the voices for the two Scottish tabby mercenaries, Angus and Duncan [=MacDougall=].
* HeyItsThatGuy:
** Professor Brody is played by Creator/JeffGoldblum. Pretty big leap, going from [[Franchise/JurassicPark math and chaos theory]] to biology.
** Shane, the police officer and lead human from the second movie, is played by Chris O'Donnell. You probably remember him from when he hung around [[Film/BatmanForever Gotham]] [[Film/BatmanAndRobin City]] or [[Series/NCISLosAngeles Los Angeles]].
** Kitty Galore's owner, Chuck the Magnificent, is played by Jack [=McBrayer=] of [[Series/ThirtyRock 30 Rock]] fame.
** As mentioned in the above trope, Friedrich is played by [[Series/SaturdayNightLive SNL]] cast member Fred Armisen.
* HeyItsThatVoice:
** Lou is [[Film/SpiderManTrilogy Spider-Man]], who then grows up to become... [[Creator/NeilPatrickHarris another]] [[WesternAnimation/SpiderManTheNewAnimatedSeries Spider-Man]].
** Butch was [[Series/ThirtyRock Jack Donaghy]]. Then he morphed into [[Film/TropicThunder John "Four Leaf" Tayback]].
** Peek is [[Film/TheGoonies Francis Fratelli]] and [[Film/TheMatrix Cypher]].
** Sam is [[MichaelClarkeDuncan none other than]] [[Film/TheGreenMile John Coffey]]. Pretty bizarre.
** Mr. Tinkles is [[Series/WillAndGrace Jack McFarland]]. And his assistant Calico was [[WesternAnimation/TheBraveLittleToaster Radio]], before he suddenly became [[WesternAnimation/ToyStory Rex]].
** Guess who the head of the dog organization is? Why, it's [[Film/TheTenCommandments Moses]]!
** Diggs [[Creator/JamesMarsden is]] [[{{Film/X-Men}} Cyclops]] and [[{{Film/Enchanted}} Prince Edward]].
** Catherine is [[Series/MarriedWithChildren Kelly Bundy]].
** Kitty Galore is [[Film/HocusPocus Winifred Sanderson]] and [[Disney/OliverAndCompany Georgette]].
* TheOtherDarrin: Lou, Butch and Calico all have new voice actors for the second movie:
** Lou was voiced by Tobey Maguire in the first movie, who was replaced by Creator/NeilPatrickHarris for the next one.
** Butch's voice actor in the first movie was Alec Baldwin, while Nick Nolte plays the part for the sequel.
** Calico was voiced by Jon Lovitz in the original movie and by Wallace Shawn in the second one.
* SavedFromDevelopmentHell: The sequel was intended for release in 2005. After some story rewrites, it was finally released in 2010 instead.
* SequelGap: A 9-year one between the original and ''The Revenge of Kitty Galore''.
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