Crowley decides that as much as he likes his plants, that maybe he’d like a pet. Not like a dog, or a cat, or a crocodile (all of which he had considered at length), but something smaller and slightly less needy.
Crowley finds himself in a pet store and spends a lot of time browsing the different tanks and cages (he got rather disappointed that this particular pet shop didn’t have many reptiles or any snakes).
He decides he doesn’t like the rabbits much, they’re too… shaky (they’re terrified of his snake eyes) or the guinea pigs (ditto). The hamsters just slept.
As he’s about to give up on the idea of pets, he sees a set of tanks at the far end of the store, full of ...rats. So many rats. In one tank that catches his eye, is a grey roan and a cremello play-fighting. He watches, fascinated and decides he must take them home, they’re perfect. So he collects the largest cage he finds in the store, and as many toys, chew things, hammocks and treats as he can fit in the cage.
He gets them home, and gets them set up and settled in. Crowley allows them a run around his apartment everyday and spends a lot of time making sure they’re well groomed and clean and healthy. He buys a pair of dungarees to wear at home just so the two rats can sit in the pouch (that is miraculously the perfect size for both of them).
One day, Aziraphale comes over unannounced, as he occasionally has done ever since armageddon’t, and notices the rats in a smaller cage without many toys, and a small bowl of food. He’s unaware that Crowley is currently washing the main cage and everything in it just as he does every wednesday morning (bonus: he’s wearing the dungarees). Aziraphale loves his spouse, but he is a demon after all, and snakes do eat rats. Aziraphale is talking in his usual soft and kind way to the two rats who are strangely calm around him, and taking them out of the cage when Crowley appears from around the bathroom.
“Hello angel! Oh, you’ve met them! I’ve told them all about you!”
Crowley very excitedly tells Aziraphale all about them and Aziraphale doesn’t have the heart to tell him that rats don’t live very long (however, they actually live for a very long time by rat standards, almost very old by horse standards), but Aziraphale is so happy that Crowley has embraced his softer side and that he’s having such a good time and he looks after them if Crowley can’t.
Extra: The grey one is named Raphael and the cremello one is called Angel (Crowley likes easy to remember names)