From Amazon.com:

Margaret Wise Brown, best known for her classic “Goodnight Moon” book, was a prolific author. Her books have been reprinted often of late, usually with a new illustrator more suited to modern tastes and the better printing techniques. In this case cat artist extraordinaire, Anne Mortimer, has been selected and the results are simply stunning.
The story itself is fairly simple: Sneakers, a plump and handsome black and white cat, accompanies his human family to the seaside for the first time. He explores the seashore flora and fauna; the repeating line is “My, I am glad I saw that.”