Dolores is a mermaid detective who worked undercover for a time as the principal of Jake's junior high school. She acted as a school administrator before Hans Rotwood took over the job, noting that she saw Jake more often than her own secretary. Though initially appearing to be a paraplegic, she was revealed to be an undercover mermaid detective seeking out the Kelpie. She also developed a relationship with Lao Shi, but left once her assignment was finished, much to their mutual regret.
- Dolores Derceto gets her name from the Syrian goddess of fertility, who took on the appearance of a mermaid.
- She was given a redesign for season two.
- Season two's closed captioning misspells her last name as "Dursetto".