After careful thinking, I've finally come up with 5 choices. These consist of Teddiursa, Celebi, Piplup, Pachirisu, and Buizel. Out of these, and of course there are more I could've mentioned but these appealed to me in the moment, I would have to choose...Buizel I think. Honestly, I'm not sure, but I can easily see it diapered, even during combat. It just looks as though it would suit the Pokémon well, naturally fitting around its curves. Meh, I was never really good at these kinds of questions anyway! <3