The 1984 CBS Saturday Morning Preview special. I actually watched this when it originally aired, even though by then I had joined a Saturday morning bowling league.
I'm mainly posting this because it includes clips from "Rabbit Rampage" and "Duck Amuck" with Bugs Bunny's lines redubbed by Mel Blanc. (And I think he did his famous "sputtering" sound effect that he originated for Jack Benny's Maxwell when Joyce DeWitt's "plane" runs out of gas.)
Also I think I saw Bill Melendez in the background in one scene. I wonder if his studio was used as the setting for this special? It would make sense since
The Charlie Brown and Snoopy Show was in production at the time. According to the end credits this special was written by Mark Evanier, so I may contact him to ask him about this (as well as why Mel Blanc didn't get screen credit in this special).