This is Sandmannchen, who for decades greeted preschool children specifically, and children generally, on Kinderfernsehen in East Germany and, then, after a brief hiatus after the rearrangement of governments, started greeting them on German children's television nationwide.  This 4x6 card is from East German days (it is trademarked by the Kinderfernsehen DDR), has never been mailed or messaged, and is in excellent condition