Frog transmutation

Nah, he's naked because he realized as a frog he doesn't need to care about that shit anymore. No laundry. No shopping for new clothes. Chill.

wizard probably had to transmute his clothes smaller to fit. not many medieval folk would likely be able to easily acquire frog sized clothing.

There's a reason you see so many frogs and so few wizards.

Just like Pickle Rick.