Doonesbury by Garry Trudeau for October 21, 1974
Zonker: C'mon, Ralphie, just one verse! Mike: Zonker! Your plants have secret lives? Zonker: No secret about it, Michael - plants are very articulate! If you listen real closely, you might be able to hear Ed the geranium recite "Gunga Din"! Plant: Did he say anything yet? Zonker: Nope. Must be asleep.