Prairie Dawn is hosting a cookie party where all the cookies are baked in all kinds of shapes! While waiting for all the guests to arrive, Prairie Dawn tells Cookie Monster that he can eat all the octagon-shaped cookies. Cookie Monster needs to figure out which cookies are octagons. He knows that the cookies that have four equal sides and angles are squares and the cookies that have three equal sides and angles are triangles, but he doesn't know what octagons look like. With help from The Count, Cookie Monster learns that octagons have eight equal sides and angles. He finds the octagon-shaped cookie and shares the cookies with his friends!