The first season of the Huckleberry Hound Show? It's comparatively easy to determine who worked on each cartoon, besides looking at the credits. The Hanna-Barbera studio had only four animators. Each did some things uniquely. Carlo Vinci’s movement doesn’t look like Ken Muse’s. Mike Lah’s Jinks doesn’t resemble anyone else’s (Lah, arguably, created the best expressions in that first year).
It gets tougher when the studio brought in more and more people, especially on uncredited bits of animation like the openings and closings of Hanna-Barbera’s shows. Muse is distinctive enough that you can tell he animated the opening of Top Cat (T.C. has expressions Muse used for Tom at MGM). Others are a puzzle.
Anyone that wondered who animated the opening for Wally Gator no longer needs to guess, thanks to a note I received from cartoonist and animator Charles Brubaker. His Patreon is here, by the way. During one of his hunts on the internet, he came across the exposure sheet on this post. You’ll notice that the animator listed at the top is Fred Kopietz, a name you generally don’t associate with Hanna-Barbera.
Kopietz is probably best known for his work for Walt Disney, though he’d spent time with Ub Iwerks and Walter Lantz in the ‘30s. He ended up at Hanna-Barbera in 1960 and was originally working on commercials.
He also told historian Mike Barrier:
Bill Hanna had three openings made [for The Flintstones] that they'd intersperse for their shows, and I did two of them. Dick Lundy—I'd animated for him at Disney's, and I gave him the third one, that I couldn't get out on time.The interview doesn’t mention Wally Gator, but it is worth your time reading it. You can find the transcript here.
Wally, as you probably know, was part of Hanna-Barbera’s first attempt to crack the syndication market without assistance of a sponsor or compiling a formal, half-hour show like Quick Draw. The cartoons were shorter than the ones making up the half-hours and TV stations could either combine them or drop them into kids programming. Touché Turtle and Lippy the Lion were the other two. Did Kopietz animate their openings? Perhaps we’ll find out some day.
Oh, by the way, I have no idea why Wally’s opening and theme song involve a swamp when the series was set in a zoo.