Peanuts by Charles Schulz for May 23, 1975
Transcript:
Snoopy lies on the doghouse. The doghouse appears to be made of brick.<BR><BR> Rain begins to fall on Snoopy.<BR><BR> Snoopy sits up. The brick lines begin to wash away.<BR><BR> The rain stops. Snoopy lies on the doghouse and thinks, "Wouldn't that unplug your heating pad!!"<BR><BR>
“Wouldn’t that unplug your heating pad!!” was also said by Snoopy on February 9, 1975. I have no idea if that line was supposed to be some pop culture reference, or if it was an attempt to make a catchphrase of some sort.