The cartoon premiered on ABC, but at some point afterwards, the rights to re-air it went to Turner-owned channels, such as TNT, TBS, and Cartoon Network.
Well, Production Company Hop- it began under DFE Films, but Marvel Comics bought them out during production and turned them into Marvel Productions, so it was credited as "Marvel Productions in association with Depatie-Freleng"; a similar thing was done for The Pink Panther: Pink At First Sight, which was credited as "A Marvel Production, in association with Mirsch-Geoffery-Depatie-Freleng and United Artists"; that special didn't have the logo symbol, but did have the synth theme (this special had a still logo, but the end theme played over it).
Like the other DFE Dr. Seuss specials, home video rights have shifted from CBS/Fox Video, to Universal Home Entertainmentnote The same studio that produced the Grinch's and the Cat's live-action movies, to Warner Home Videonote Which already acquired the animated How the Grinch Stole Christmas! through its acquisition of the pre-1986 MGM library.
The Other Darrin: Bob Holt and Mason Adams take over the roles of the Grinch and the Cat respectively, as their original actors, Boris Karloff, Hans Conried, and Allan Sherman, had died prior to production.