This is the second OK K.O.! crossover with other Cartoon Network/Warner Bros. universes (Steven Universe and Mega Celestial Maia in particular) but the first one to be a movie.
Kermit the Frog from The Muppets makes a cameo in this movie.
In addition to him appearing, other lookalikes of Muppet characters are seen as well.
King Ghidorah, one of the most famous kaiju in the Godzilla franchise, was one of the monsters and villains living in the apartment building. This could be a reference on how typically Asian people (Japanese ones in particular) live in foreign (American ones) apartments at Metropolitan areas like those in New York City (especially with Brooklyn and Manhattan), Tampa, Chicago, Atlanta, Denver, New Orleans, Miami, Los Angeles, Sacramento, San Diego, Detroit, Jacksonville, Cleveland, Seattle, Boston, Honolulu, Cambridge, and Philadelphia.
In addition, a look-alike of Camera make an appearances. Caricatures of Goro and Sheeva are also seen, albeit with them being more Human looking appearances.
There are some soundtracks from SpongeBob SquarePants of the funny parts.
Unlike the series Steven Universe, Jasper finally becomes a protagonist in the movie instead of an antagonist.
The roar Jasper makes has the roar from the T-Rex in Jurassic Park.
Mega Celestial Maia first appears in the OK K.O.! Let's Be Heroes! crossover.
