"The Adventures of Superpup" (1958) was meant to be a children's show with little people in dog costumes. Billy Curtis, star of 'Superman and the Molemen,' played Bark Bent who was a reporter working for Perry Bite. When the evil Professor Sheepdip kidnaps Pamela Poodle, it's our hero to the rescue."

"Instead of people, the entire cast dressed up in dog costumes. The dog heads were just big masks so they couldn't move their lips. You'd have to hear their voices without seeing any facial expressions or movements. That was one big drawback. "

Show descriptions and frankly weird-ass images can be seen here, here, and here.

Via Monkeyfilter

Also, the Gotham Girls Wikipedia entry links to the first 20 episodes of the Warner Brothers / Noodle Soup internet Flash cartoon show, and shows you how to get around the "loader" files Warner Brothers keeps the last ten of the 30 shows behind. Gotham Girls featured the Harley Quinn, Poison Ivy, Batgirl and Catwoman characters from the various Bruce Timm/Paul Dini animated Batman series of the 90s.

Gotham Girls [Wikipedia]