Who or what besides "Mister Rogers" and "Sesame Street" can you think of as an example of didactic (teaching) entertainment for kids?

Doesn’t have to be TV; could be books or other media.

I’m interested mainly in highly recognizable characters or sources that use storytelling as a teaching vehicle—stories like Aesop’s fables that are meant to convey a lesson or instill a principle.

I’d like to be able to make a reference as brief as a mention of Aesop and have the idea come across. I haven’t seen much in the way of kids’ teaching materials since the mid-1980s. Is there anyone or anything now as familiar and iconic as the old PBS mainstays?