Raining cats and dogs is an idiom (expression) used when it is raining heavily. The first recorded use of a phrase similar was in 1651 by a British poet Henry Vaughan. He referred to a roof that was secure against "dogs and cat rained in shower".
Abstra-Cats do not want to rain with dogs so it is simply 'Cat Rain'. Notice how 'Cat Rain' shapes are curvilinear and in close proximity to each other creating a sense of unity.