Slethy loves cooking, a fairly commonly known fact about him, given he'll quite happily cook for nearly anyone if he gets the chance, finding the process nearly as enjoyable as the delicious results themselves~!
Something that many might not immediately think about though is that cleaning is necessary too, sometimes beyond just cleaning up what he's used for cooking too, making sure all surfaces are nice and clean. Fortunately, he finds that quite enjoyable too, though his size when a Serperior does make reaching certain spots a little troublesome, so it's a good thing he has some means to temporarily de-evolve into a Servine or, in this case, Snivy~
The maid dress is just because he likes wearing one honestly, it makes the cleaning just a little bit more fun~
