Watch Out... It's a Cat! is a Hamtaro board book. It is a rather rare book to find in English, since it was supposedly released in December 2005, even though Hamtaro went off the air in the US in October 2004 (though Canada saw reruns until 2006, so it may have been a Canadian release). Amazon UK claims it was released in 2006, so the true release (if there was any) is a mystery. At any rate, it is now out of print, so if anyone owns the English version, they should consider themselves lucky:
The Japanese version, however, is readily available to purchase for a reasonable price:
The description from Amazon.com:
The cute and cuddly pet of fifth-grader Laura, Hamtaro is a golden hamster with an insatiable curiosity. Together with the Ham-Ham Gang, a bunch of hamsters as clever and unique as Hamtaro himself, Hamtaro lives each day as a whole new adventure ... complete with fun, excitement, and friendship. In this imaginative board book with a hole cut through each page, the picture and story change with each new page. On the first page, Hamtaro and his Ham-Ham friends think they see a cat about to pounce on them, but as the story unfolds and the pages are turned one by one, the scary "cat" turns out to be anything but.