I found this 1971 Hanna Barbera Square Bear mug for a quarter at a garage sale yesterday.
Square Bear is from the awkwardly-named show "Help!... It's the Hair Bear Bunch!" a show which I was never particularly fond. It was a little before my time and by the time I did see it, was very dated.
It's not worth a lot, so it will get added to my collection of character glasses.