Hers ia another character form the comic book idea I have rattling around in my head. This is Petey and Goblin. They go with Shadow and Girl. Same story, this is the guy who was directing the film the kids were making when they accidentally summoned demon monster things and bound them as familiars. You may ask, why did they do that and the short answer is they didn't know what they were doing. They thought they were using some novelty, fake magic book they got from a local thrift store. Turns out it was real. They were left with a choice of binding the monsters as familiars or letting them roam the earth to do what mischief they could before being banished or called back. Not wanting to be responsible for unleashing the potential terrors on the world the kids finished the ritual and bound them. Sometimes they wonder if they were lied to and there was another way, but they are stuck now it seems.
Petey got the short end of the bargain it would seem, the other two kids are being taught real magic and they can do some pretty cool, if somewhat scary, stuff. All Goblin can seem to teach Petey is a summoning spell, that summons more goblins. Lots more goblins. You would think having an army of little purple minions to do what you say would be cool, but you'd be wrong. Goblin and his brothers are stupid. They know "Attack", "Eat" "Take" (not Fetch, they tend to keep whatever they take) and occasionally they will obey the order to "Stop" but not always. So Petey is sort of the Thelma of the group. He is timid and shy and envious of the others for appearing self confidant and in control, but Petey is the brain of the group and can logic his way through of a lot of issues, so hes got that going for him.