Princess is the pet dog of Mr. Fuller and Mrs. Fuller, who hired Greg to look after her while they were gone in Rodrick Rules. She was, as Greg put it, "gun-shy" about going to the bathroom in front of strangers, causing her to make a mess in the foyer. Her online counterpart is Stevie.
- Diary of a Wimpy Kid Online (As Stevie)
- Diary of a Wimpy Kid: Rodrick Rules