Jeff was an Easy Breezy brand shoe box with the name "Jeff" written on it. Tina thought Jeff was a ghost who lived inside the box, but it turned out that Louise Belcher tricked her in to thinking he was a 13-year-old boy, after an exterminator said there was a ghost in the restaurant. Thinking he was a boy, Tina started a relationship with Jeff and took him to a Butterfly exhibit, a park, Wonder Wharf, and to school.
Jeff proved to be popular, increasing Tina's popularity in the process. Jeff was stolen from Tina by Tammy. Eventually, Tina learned that Jeff wasn't real, and tricked Tammy into confessing.
- It is unclear if Jeff should be referred to as "he" or "it", as the name "Jeff" may be applied to both the physical box and the imaginary ghost inhabiting it.