Despite the show's title, Fred and Barney never actually meet the Thing. Instead the title represents the two half-hour segments that make up the hour long show.
The Thing is the first half of the Hanna-Barbera produced show and has virtually no tied to the Fantastic Four character or comics at all. Instead, Benjy Grimm is a nerdy teen at Centerville High School who has two magic rings. When the rings are touched together and the magic phrase (Thing ring, do your thing!) is chanted, Benjy turns into the ever-loving, blue-eyed Thing!
Benjy hangs out with his friends Betty, Ronald and Kelly, and thwarts the bullying attempts of Spike and Turkey of the Yancy Street Gang.
Each half-hour episode contained two stories. The show debuted on September 8, 1979 on NBC. A few months later a new show, The New Shmoo, was added making the show 90-mintues. The title was changed to Fred and Barney meet the Shmoo.
Benjy Grimm - Wayne Morton
Betty - Marilyn Schreffler
Kelly - Noelle North
Ronald Radford - John Erwin
The Thing - Joe Baker
Miss Twilly - Marilyn Schreffler
Dr. Harkness - John Stephenson
Spike - Art Metrano
Turkey - Michael Sheehan