The Brown Hornet, Spaceman Spiff and Marvin the Martian

I was a big Fat Albert and The Cosby Kids fan growing up, I even remember having a Fat Albert lunch box for a while.  I loved Bill Cosby's stand up comedy records and it was cool for me to see his childhood in animated form.  Of course, I thought it was cool when they introduced the show-within-a-show The Brown Hornet, adding a superhero element to the program.  I always thought that he could have had a life beyond the series, but I never saw anything from him after it went away.