The correct answer is “One.” That person is Gerard Baldwin.
Mr. Baldwin had two tours of duty at the studio. The first one was brief. He worked on a handful of cartoons on The Huckleberry Hound Show and The Quick Draw McGraw Show in 1959 before he left for a job with Jay Ward working on a new series called Rocky and His Friends (a Hanna-Barbera background artist named Joe Montell left around the same time for the same reason). He returned 20 years later to toil on programmes like The Smurfs, where he was a supervising producer. In between, he lent his talents to Mr. Magoo’s Christmas Carol, the first animated TV special, the wonderful Super Chicken and numerous other shows and commercials.
There are so few of the old-time animators left that it’s getting rarer and rarer to hear first-hand accounts of what went on in the growing days of television cartoons. But not only is Gerard Baldwin around, he’s written a book. It was published last December but I’ve just learned about it now. Whether he discusses his first go-around at Hanna-Barbera and the excitement of animating a Yowp cartoon, I don’t know. But it does take him through his start at UPA in the early ‘50s and beyond. You can read a little more about it HERE.
Since we’re discussing Mr. Baldwin’s early H-B work, here are some frames of his drawings we’ve posted elsewhere.
Bear Face Bear, layouts by Walt Clinton.
Dog Gone Prairie Dog, layouts by Walt Clinton.
Big Top Pop, layouts by Bob Givens.
Adventure is My Hobby, layouts by Bob Givens.
Monkey Wrenched, layouts by Bob Givens.
Bear For Punishment, layouts by Tony Rivera.
Six-Gun Spook, layouts by Bob Givens.
P.S.: Givens and Sam Clayberger are still with us and worked on H-B cartoons before 1960, but Givens was in layout and Clayberger was a background artist. It’s a shame a Givens autobiography has never been published.