The fox in Sir Gawain and the Green Knight symbolizes wisdom and cunning. It’s also a symbol of trickery and deception, but those qualities are positive ones in this story. The fox represents the wild and untamed side of nature, as well as fertility and abundance. It represents good luck and fortune because it is often seen as an omen of good things to come—the same way that it can also be an omen of bad things to come.
The fox is an animal that is both smart and strong, which makes it a powerful symbol for intelligence and cleverness. It also has gracefulness and beauty associated with it, which makes it an attractive symbol for humans who want to emulate those traits in themselves.
But there is also mystery associated with the fox: its behavior is unpredictable, so we don’t know what will happen next when we encounter one of these animals in real life or in stories like Sir Gawain and the Green Knight (where there are several instances where a fox appears).
And finally, the fox is associated with magic because we don’t understand how they can do certain things—like how one might disappear into thin air just like a magician would do on stage.