Gif: POTION PREDICAMENT (Patreon)

Doctor Oliver had spent years working on a youth potion with little success. When he learned that one of his rivals had actually developed a working potion, Oliver went mad with envy and conspired to steal the potion for himself. He poisoned his rival, gulped down the potion and smiled as he felt himself becoming younger. But then something went wrong. He was becoming younger and younger, smaller and smaller... and what was this long, golden hair, falling in his face?

Sorry for the kind of cruddy resolution on this gif. It was the best quality I could find, but the scenario was so fun I couldn't resist it!