Each row or team sends a representative to the board. They choose a coloured pen or piece of chalk and they stand in a line. You write a letter and the first student must write a word beginning with that letter. Then the following student writes a word beginning with the last letter of the previous word, and so on. For example, if you choose the letter D, the words could be:
data amount tomato on narrow what ...
However, the students should write the words so that they merge together into a 'snake':
datamountomatonarrowhat ...
Limit the time for each student to write the next word, depending on the level of the class. After their time has passed, if they haven't written a word then they miss their turn. If you miss your turn three times, you are replaced by another student from your row/team. Only two replacements are allowed. After that, the row/team is eliminated.