These cups and coasters redefine cups with designs that change when hot beverages are added. These borosilicate glass mugs have an interesting slanted shape and unusual stick handles, but they are otherwise plain when viewed from the side. They have a fish-shaped metal piece on the bottom, and when you fill the mug with a hot beverage (about 155 degrees F) and set it on one of the plain, black acrylic coasters, you’ll discover their surprise. The heat transferred from the metal plate on the bottom causes a bright, fish-shaped design to appear on the coaster. The design will fade as the coaster cools, waiting for you to place the next fish. A set of two Interactive Fish Cups and Heat Pads costs $50 from CKIE.