Jonathan began to feel very strange.
A long frog tongue shot outta his mouth and got a fly. His eyes grew wide.
"What gives?" he wondered, scratching the back of his neck, and it was then he suddenly felt a slimy feeling on his hand, which also made it seem cold and wet.
he took a better look at it to find it painted with a pale green hue, as if he was sick.
He looked in the mirror, and gasped. his face was pale green too.
he lifted up his shirt & lab coat, and was surprised to see that his torso was tinted green with brown-yellowish spots covering all over him.
he took off his shoes and socks, and watched as his feet were elongating right in front of him, like in transformation scene from "An American Werewolf in London". The toes grew freakishly long and webbing formed between them. Jonathan tried taking steps with them. He walked as if he had swimming flippers on his feet.
Then, his walking turned into small hops.
Then, suddenly, in a heartbeat or two, Jonathan immediately shrunk into his clothes with a poof!
A frog with Jonathan's human face appeared, sitting on his human self's discarded clothing. his hair was unchanged.
"Ribbit." croaked Jonathan. he tried to say something else, but all that came out of his mouth was "Ribbit!"
Jonathan had transformed into a frog!