In 1981The Dayton Daily News twice accidentally mixed up the captions for Dennis the Menace (American version) and The Far Side, making the family-friendly Dennis the Menace cartoon appeal to a more mature audience.

Far Side illustration: Three snakes (mother, father and child) sitting down for dinner. The grumpy child snake speaks.
Mismatched caption: Lucky thing I learned to make peanut butter samwiches or we woulda starved to death by now

Dennis the Menace illustration: Dennis and a friend carrying sandwiches walk past Dennis's mother, who is busy talking on the phone. Dennis speaks.
Mismatched caption: Oh, brother ! ... Not hampsters again !

A few weeks later the same kind of mistake was repeated...

Far Side Illustration: Two neanderthals are in a cave: a fortune teller with a crystal ball, and her customer. The fortune teller speaks.
Mismatched caption: If I get as big as Dad, won't my skin be too tight ?

Dennis the Menace illustration: Dennis and his parents are sitting down eating dinner. Dennis looks up at his mother and speaks.
Mismatched caption: I see your little, petrified skull...labeled and resting on a shelf somewhere