"Well, if you're a witch, then you probably need a black cat, heh heh," chuckled Damon.
"I'm not sure 'need' is the right word, but they do come in handy," answered Circe. She waved her wand over Damon a few times until he felt a twitching down in the back of his pants. Some new part of himself flailed around in the seat before pushing them down and emerging out over his belt into the open air. Damon looked back and saw a black furry tail sticking straight out behind him. He grabbed it and was shocked to feel his hand around it. He looked back at Circe and tried to say something, but all he could do was meow.
Damon's clothes were getting looser as he was now obviously shrinking. Looking down at his hands, black fur was growing all over them and he no longer had fingernails on the top of them. Instead, he had retractable claws that he could flex out between his padded fingers. A bunch of really long hairs on his face (whiskers) were starting to twitch.
Damon's shirt was starting to fall down around his torso as his ears grew up into points above his head. Soon there was nothing left of Damon except a beautiful jet-black house cat untangling itself from a pile of clothes. Circe smiled while Damon looked around in a daze.
"Well, Damon. Thank you for volunteering to be my new pet. I look forward to having you here. Let's get this needless clothes out of the way and get you some enjoyable new cat things."