This tiny book is one of 6 different titles (including Captain America and Thor) released in 1966. They were sold via gumball machines in various colors (blue, yellow, red, green).
These books are regarded as the tiniest comic series in the world measuring 5/8 in. x 7/8 in. Basically the size of a quarter. When the Incredible Hulk’s original six issues ended in 1963 with #6, this tiny book was released three years later and could be construed as an Incredible Hulk #7.
The pages of this tiny book are fused together but could be pulled apart if desired. I have decided not to open this one in order to maintain its quality. The story seems to be more or less an overview of who and what the Hulk is and does. There are pictures and videos available online to see the interior pages. Though they seem to be simply pictures with the opposite page having a small blurb describing the image.
I was able to win this book in an auction for about $20 but most places are asking $60 given their low availability.
I keep this little guy safe in very capable hands.