Aurae are wind spirits that can be found working at Camp Jupiter.
Aurae work in the Dining Hall of Camp Jupiter in a capacity similar to waitresses/waiters can be found delivering food to the campers. For example, Percy Jackson was given a cheeseburger and a blue soda his first night at Camp Jupiter, while Hazel Levesque was given shrimp gumbo, her favorite comfort food. Aurae fly relatively close to the ground and stay invisible most of the time, meaning if someone stood they could be hit in the head with a plate, much like when Don the faun was hit in the face with a pizza. Hazel comments that they blow plates and cups around so quickly, that it looks like a delicious hurricane.
Aurae appear once again after the battle with the Giant army, delivering food to the campers at terminal velocity. Tyson kept ordering peanut butter and jelly sandwiches and would eat them almost as fast as the aurae could provide them while Ella was given a cinnamon roll.
Aurae are invisible most of the time, although when Percy grins after drinking his blue soda, one becomes visible for a moment and tops off his glass with a giggle. She looks like an elfin girl in a white silk dress, but it is unknown if all aurae dress in a similar pattern, or if the style of dress is favored by only that one.