Check out this great design from cafepress Bitter Litter Cat Mug
Bitter Litter Cat Mug. This little animal says "litter make me bitter, please don't trash my home!" If you hate litter bugs, then these great designs are perfect for you. Tell everyone that the litter needs to stop. Product Information Small measures 3.75" tall, 3" diameter; Mega measures 4.5" tall, 3.75" diameter Small holds 11 oz.; Mega holds 20 oz. Black color-changing mugs available in small only and are heat sensitive. The color-changing mug starts out all black in color. Simply add any hot liquid to the mug and watch as the mug changes from black to white and your unique design is revealed! Dishwasher and microwave safe
