Shelby has a cardboard box for a body, with different-colored designs drawn onto it. The box has an opening for her mouth, with light pink lipstick around it. Coming out of the sides of the cardboard box are gray foil arms, with pink oven mitts at the ends. She also wears a pair of dark blue roller skates with red-orange wheels. Lastly, on her head she wears the head of a mop as a wig, along with a bucket and a pair of antennas.
Role in episode
SpongeBob, dressed up as Shelby, is taken by Plankton to the Chum Bucket for a romantic date, with the plan being for them to make Karen jealous. However, after dinner and romantic talk, Shelby goes overboard and reveals her love for Plankton, making Karen accept that the two are in love. This causes Plankton to remind Shelby about the entire point of the plan, making Karen realize that Plankton does care about her.