Goober and the Trucker's Paradise [pilot only] to Love That Bob

Goober and the Trucker's Paradise was a failed spin off of Mayberry R.F.D. that instead ran as a one-shot special that had Goober Pyle running a truck stop.

was a spin off of The Andy Griffith Show

Gomer Pyle, U.S.M.C was a spin off of The Andy Griffith Show

The Lucy Show's Lucy Carmichael was accidentally drafted into Gomer Pyle, USMC's company on an episode of The Lucy Show.

Here's Lucy's Mary Jane Lewis was originally a character on The Lucy Show (also called The Lucille Ball Show).

Here's Lucy's Lucy Carter was visited in two episodes by The Bob Cummings Show's Bob Collins.

The Bob Cummings Show was repackaged and ran in syndication as Love that Bob.