Tom Karen arrived in the UK as a refugee in 1942, having fled the Nazi occupation of Czechoslovakia. He made a career in the British design industry where he became head of Ogle Design and was responsible for the original Kiddicraft Marble Run and the Raleigh Chopper bicycle. After retiring, his love of children prompted him to run workshops for them and design and make toys and games for his grandchildren. He also started drawing animal bottoms on tiles for young friends. They are the subject of A Little Look at Bottoms.