Stink and the Freaky Frog Freakout #8 by Megan McDonald illustrated by Peter H. Reynolds*

My eight year old read this book to himself.
Stink is struggling learning to swim.  Because he won't put his face in the water, he must remain in the polliwog swim group.  Stink is also encountering a lot of frogs--some of them with mutations.  Maybe if he mutates into a frog, he will learn to swim?
*Highly recommend.
-Borrowed from the library.