First appearance of Hippety Hopper.
Hippety Hooper looks most like a realistic kangaroo in this episode. He would become more comic in his appearance as the shorts progressed.
The appearance of Sylvester and his bulldog nemesis would evolve over the years as well. They are shown more true to life here.
The fitness craze, or a very early version of it, was taking off in the postwar years. But most of it was geared to the sport of boxing, as shown here.
"Time to get on the water wagon" meant it was time to abstain from alcohol.