Some claim that the saying “curiosity killed the cat” is a transmutation of “care killed the cat” (by “care” meaning sorrow). Maybe not. The Washington Post reported in 1916 — headline “Curiosity killed the cat” — about a cat named Blackie who climbed up a chimney apparently out of curiosity, could not come down, climbed higher, fell and eventually died (source).
So, who coined the saying “curiosity killed the cat”? The sensational press did.