Frog on a Log? by Kes Gray illustrated by Jim Field

Cat informs frog that he must sit on a log because that is what frogs are suppose to do.  Frog, however, does not like that idea because logs are "hard and uncomfortable and give you splinters".  Cat proceeds to share on what specific animals must sit.  The animal's sitting spot rhymes with their name (cat=mat, hare=chair, mule=stool, gopher=sofa etc.) so this book can be used to reinforce rhyming and some word families.
The ending is funny!
Borrowed from the library.