Neko Natsu

Natsu, Lucy, and Happy went on a mission to capture a cat burglar that uses some kind of magic to slip in and out of houses. When confronting him he throws a potion at them then makes a quick escape. Natsu pushes Lucy and Happy out of the way just in time so he only got hit. They later find out that the potion changed Natsu's looks and attitude so he ACTS like a cat. And of course Lucy has to take care of him while the guild looks for a cure.