Waomi Natts is a one-off character in Chapter 31: Jeremy Bearimy, played by Kathy Luu. She is a shop assistant who tells Chidi that he cannot walk around a supermarket without a shirt.
In keeping with the Australian setting of S3, Waomi Natts is a spoonerism of the actress Naomi Watts, who though British, is often thought of as Australian since she began her career there. Although given this name in the episode's credits, her name badge in the episode clearly reads "Julie".