There's an argument to be made that Rocko's Modern Life was not for children, but it aired on Nickelodeon in the afternoon, so we watched it. And this is poignant as hell-
R-E-C-Y-C-L-E Recycle!
C-O-N-S-E-R-V-E Conserve!
Don't you P-O-L-L-U-T-E.
Pollute the rivers, sky, or sea.
Or else you're gonna get what you deserve
...I still sing it to myself sadly when I read the news sometimes.