These 6 square <a href="http://www.uwgb.edu/DutchS/symmetry/aperiod.htm">Raphael Robinson tiles</a> fit together in a pattern which never repeats itself no matter how many tiles you use. You can play around with the tiles by cutting up the picture on the card.
The six tiles are:
<li>A green present with red ribbon
<li>A christmas tree
<li>A red ribbon
<li>A moon and stars with Santa and his sleigh riding in front of them
<li>Holly and ivy