There are several synonyms for the phrase "play the fox," which means to act sly or cunningly. One such synonym is "play the coyote," which denotes similar behavior in a more mischievous and aggressive manner. Another synonym is "play the possum," which suggests playing dead or dormant to deceive others. "Play the weasel" is another synonym that describes someone being deceptive or deceitful in their actions. Finally, "play the snake" is a synonym that describes someone who is slippery and cunning in their dealings and actions. While these synonyms may all have slightly different connotations, they all share the idea of acting cunningly or deceptively.