Question: Steve Marmel has worked on many animated TV series, including what series that was created by Butch Hartman for Nickelodeon?
Sentence (from "Danny Phantom"): The series follows a teenage boy who, after an accident with an unpredictable portal between the human world and the "Ghost Zone", becomes a human-ghost hybrid and takes on the task of saving his town (and the world) from subsequent ghost attacks using an evolving variety of supernatural powers.
Relevant evidence: No