What figurative language is “I wanted to stare at the rainbow, but it was raining cats and dogs.”

idiom

Explanation:

a saying a idiot would believe

moon-letters were a method of writing invented by the dwarves. moon-letters were ordinary runes, but written in such a way that they could only be read when the light of the moon shone behind the writing. some moon-letters could be read by any moonlight, but it was possible to make the writing even more secret. more sophisticated moon-letters could only be read by the light of the same shape of moon, or at the same time of year, as when they were written. hope this !

lemme actually be useful and say i believe the answer is the first one.