Check out this great design from cafepress Tree Hugger Mug
Tree Hugger MugTree Hugger Mug. If you care about the environment then this great tree hugging boy will delight you when he shows how much he loves this tree. 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
