This achievement requires first that you are playing a Casual puzzle with one other member of your team. Your teammate first needs to complete a single word to earn 100 points. This is generally one of the longest words in the puzzle. Before they answer it, place a x2 power-up on the word to guarantee it is over 100 points (you or your teammate can place this). Once they complete the word, drag the Copy Cat power-up (it looks like a cat) and place it on the already-completed word to copy the score and unlock this achievement.