Hee! The classic cat!Snape fic is probably treacletart's Nine Lives of Severus Snape (written 2004 or earlier), and I wrote a cat!Snape drabble for a friend whose actual cat is named "Snape" ... but I swear I wasn't thinking of either of those when I drafted this: he happened to show up when I needed to make the soup disappear. ;-)
I'm glad you liked it - thank you for putting your art in the challenge! I got to the claiming late and was delighted to find something so nifty up for grabs. :-D