Wendy and Marvins' Show

King Plasto and his Toyman-sounding sidekick are using plastic to make phony distractions and factories to steal things.
This was all Wendy and Marvin's show as Marvin and Wonderdog find the secret cave, only to be jeered by Batman and Robin, until later they realize the cave is real.
Once again, it is Wendy and Marvin who figure out how to open the secret cave as Batman and Robin leave.
Love the snappy quips between Batman and Robin as they discuss hurrying to a destination.
"With light traffic, we should make it in good time" Batman says, then off goes the Batmobile.
Nifty twist that I had to recall with King Plasto's informant.
Just an original Superfriends cartoon, if nothing else.