*Jenni Anderson is Martin's constant—and rather unrequited—love interest. Her view of Martin is generally not very flattering: this includes "immature", "freak", and "loser". She has a crush on Marvin, the skate boarder guy that perfectly looks like Martin but there have been times where she is actually interested pursuing a relationship in him, such as when he acts like a gentleman. Unfortunately for Martin though, it never lasts because her mind is erased of whatever happened such as whether Martin does something stupid, she moves for a semester, or if some other similar incident occurs. She is also Diana's best friend.

As one of the prettiest girls in school, Jenni is constantly a target for Martin's well-intentioned romantic gestures. Whenever she appears, it is to typically show how incompetent Martin is with girls. She is also Diana's best friend and whenever she isn't at the tail end of one of Martin's intentions, she is seen either hanging out with Diana or chatting with her.

While she has a major dislike towards Martin and eventually Billy who was now wearing a body suit to look like a normal teenager, on rare occasions she takes a liking towards him. One occasion when he was being possessed by Gastromo, he was acting sensibly and agreed to out with him. Another being when she was under a spell played by Martin when he was using a guitar, she alongside the other girls at Torrington except Diana turned into love monsters. This spell however was broken when the song that Martin had been performing was played backwards. On another occasion while working at Terrorland, Martin saves her from a zombie which she is grateful for but even more shocked to discover that Martin was a secret agent for the paranormal explaining his interest in the paranormal. When hiding from a group of zombies she even tells the monsters to stay back from them or she would set Martin on them, she even tells them that he is her boyfriend, after defeating the scarab monster she asks Martin to go on a date with her and asks if she can join him and work at the center. Her memory from this event however ends up getting erased and she goes back to disliking Martin for his interest in paranormal rubbish. The episode Journey into Terrorland is the one time that Jenni discovers Martins identity as a secret agent working at the Center. She gets an instant crush on Martin and eventually asks Martin if he will go on a date with her and asks him to tell her all about his secret identity as she now wants to become an agent and work with him. Her memory however gets erased afterwards and she forgets the whole incident and Martin's secret identity. She has an interest in pirate clothing as she loved Martin’s look while he was under the spell of Captain Blood.*