Fables of the Green Forest
Fables of the Green Forest was a 1973 Japanese anime television series based on a beloved series of children's books by Thornton W. Burgess of the same name.
Essentially, the show was about a bunch of anthropomorphic animals living in, well, The Green Forest, with the stories focusing mainly on Johnny or Rocky (depending on your viewing region), a woodchuck (or, if you take the Japanese translation of his name, literally: "Rocky Chuck, the Mountain Rat"...I mean, c'mon!), his mate, Polly, and, to be frank, all their dim-witted animal friends (and enemies). Simply put, it's wonderful grist for riffing mill and it should not be neglected.
There were 52, half-an-hour, episodes in total but I thought, maybe, it might be comparable to the same kind of serial riffing that you did for that 1940s Batman stuff.
I would also imagine that the FotGF would be both easy and cheap to obtain, if you needed to be further sold on the idea.
Shrugs