As we know, Mel Blanc was a member of Jack Benny's repertory company, both on radio and on television. At the peak of the TV version of The Jack Benny Program, Benny was persuaded to step into Blanc's world, if you will, and star in an animated cartoon.
"The Mouse That Jack Built", released in 1959, features Benny and most of his troupe, particularly Blanc, Mary Livingston, Don Wilson, & Eddie "Rochester" Anderson. As you'll see, the real Benny appears at the end of the story, and he appears to have dreamt the entire tale, but for a slight twist.....! Uploaded by hyrail73:
This has aired on syndicated Looney Tunes compilations, but I'm not sure if it turned up on network television.
Of course, being that it's Cinco de Mayo, I couldn't let this next offering pass. From an episode of The Jack Benny Program, here's Mel Blanc as a Mexican tourist in a variation on a routine that Mel & Jack did on radio. Uploaded by TVRewind:
"The Mouse that Jack Built" merits an A.