In the Pokemon world we RP in, since I use a variety of "mew" characters (who are universally very potent beings), I also wanted to provide them limitations to help keep them dynamic and situational. Since they can all transform, I set a limit on that, in that what they turn into must be around their size for the best benefit. Anything larger or smaller will have some intense strain on them. As such, they can only hold more dynamic forms for a manner of hours, minutes, or in the case of a great legendary, mere seconds before they are forced out of it.

And in a world where they much rely on Transform to get around, they have turned it into an art form of sorts.

Humans are one of the more complicated transformations. Only the stronger of the group can maintain a human form for a palpable amount of time. Most mews don't bother, but Butters, in the name of science and discovery, will do anything to intermingle with other humans.

Being a considerably weaker mew than the norm, Butters compensates by taking... shortcuts.