Freddy Martinez and Cara Simonetti
Portrayed By: Zach Lipovsky and Meredith Henderson (TV)
Two best friends whom end up in the clutches of Count Nightwing.
- Adaptational Nice Guy: They (Freddy in particular) is much nicer in the episode than they were in the book. He isn't shown picking on children as a babysitter at all, and they get along pretty well as brother and sister.
- Adaptation Name Change: Their surname in the episode is both Renfield.
- Ambiguously Brown: Freddy's last name is "Martinez", which is typically a Spanish surname, and Cara's last name is "Simonetti", which is typically an Italian surname. Also, they both have black hair and dark brown eyes, which usually occur in non-Caucasians. Averted in the episode, in which both are clearly white.
- And Then John Was a Zombie: Once Cara gets werewolf essence spilled all over her, the book ends with her growling at Freddy. Whether Freddy became a werewolf as well (even though he was just revealed to have been a vampire like his family) is unknown.
- Babysitter from Hell: Freddy constantly torments the boy he's babysitting, Tyler Brown, with scary stories and tickles. His returning parents are not amused by this, and scold Freddy, though they reluctantly pay him.
- Averted with Cara. She might be rude at times, but she's shown to be a much nicer babysitter, telling Freddy to stop harrassing Tyler and wrestling him away.
- Break the Haughty: They definitely lose their cool personalities when they encounter the adventure in store for them.
- Curiosity Killed the Cast: Their Fatal Flaw. Once they find a secret door in the house, they instantly open it, which brings them to Count Nightwing's coffin. Once they see a strange bottle on the floor, Freddy instantly opens it, which causes the vampire in said coffin to awaken. When Cara finds a bottle of "Werewolf Sweat" in the kitchen cabinet, she instantly opens it, making her werewolfish.
- Does Not Know His Own Strength: Freddy notes this almost word for word when he and Cara get in a scuffle that results in the secret vampire entranceway being revealed. He jokingly pushes her into the basement wall, which caused her to lose her balance and slam hard into a china cabinet. Luckily, the cabinet didn't fall over and none of the dishes were broken. But Cara furiously takes the fight even further, resulting in the cabinet falling over and the plates getting broken anyway.
- Jerk with a Heart of Gold: They are quite rude (especially towards each other), but when it comes to protecting each other from the vampires they come across, they don't hesitate.
- Nightmare Fetishist: They tend to behave tough, like scary moments, and enjoy watching scary movies. However, when it comes to encountering dangers involving an actual vampire, they don't have much to show.
- Related in the Adaptation: In the book, they are friends who just so happen to look like siblings. In the TV episode, they are twin siblings, whose last names are changed from Martinez and Simonetti to Renfield.
- Too Dumb to Live: They definitely aren't worthy of protecting themselves. Once they see a window leading out of the castle (which, by the way, they had known earlier was a place that was built beside a jutting cliff), they instantly jump through it without looking down, resulting in them plummeting from a fearful height. If it wasn't for Count Nightwing swooping in to save them, they would have made a large splat.
- And after her whole vampire event that occurs to her, Cara goes to the bathroom in Freddy's house and finds a bottle of werewolf sweat in the cabinet. Even though she just saw the dangers of opening up a bottle of Vampire Breath would result in, she foolishly opens this bottle up to see what's inside. This doesn't work out for her.
- Vitriolic Best Buds: Their fighting is so intense that one must wonder how they became friends in the first place. They actually like it, though, and Freddy thinks that their friendship wouldn't work out if they didn't do this.
- Women Are Wiser: Cara is usually this. She tells Freddy to knock it off with picking on the child they're supposed to babysitting. And when Freddie begins to open up the Vampire Breath he's holding, Cara tries to stop him, as it could be dangerous. This is much averted in the ending, in which she comes across Werewolf Sweat instead, and Freddy is the one who tries to stop her, but fails.
Count Nightwing
The great grandfather of the Martinez family, Nightwing is a powerful vampire lord who derives his abilities from a mysterious substance called "Vampire Breath". Eventually, his grandson accidentally wakes him up from his centuries long slumber. Nightwing only wants to return to his own time, but is willing to involve children in his plans.
- Affably Evil: Aside from being a vampire, he is actually a pretty decent guy, and even saves Freddie's life at some point. Even when he promises to turn him and Cara into vampires, he doesn't seem to realize they don't see it as a good thing.
- Big Bad: Of Vampire Breath.
- Blue-and-Orange Morality: His idea of helping Freddie and Cara is to turn them into vampires so they can live along with him in the castle, since he doesn't know how to send them home.
- Our Vampires Are Different: Mostly follows the Classical Movie Vampire archetype, with the only notable difference being that he needs to drink Vampire Breath in addition to blood.
- Ungrateful Bastard: When Freddie and Cara help him return to his time period, he repays them by refusing to help them get home and promising to turn them into vampires as soon as he finds his fangs. Then again, he genuinely seems to believe that would be doing them a favor. As it is, he claims that he doesn't know how to get them back to their own time, so his refusal isn't necessarily just because he's evil.
- Villainous Rescue: While in his castle, Freddie attempts to escape by a window, only to nearly fall to his death. Count Nightwing ends up saving him in bat form.
- Weaksauce Weakness: He can't feed without his fangs, and he needs Vampire Breath to remind him where he left them.
Gwendolyn
Portrayed By: Krista Dufresne (TV)
A young girl Freddy and Cara meet while exploring Nightwing's domain, claiming she was a captive of the vampire.
- Decoy Damsel: She passes herself off as a human who's a slave of the vampires, but is really (and quite obviously) a vampire herself and tries to bite the protagonists herself (Book) or take the Vampire Breath to overthrow Nightwing (TV).
- Exact Words: In the book she tells Freddy and Cara that "she knew a way out" from Nightwing's domain. Turns out her interpretation was for her to bite the two.
- Face-Revealing Turn: In the book, she does this when she thinks she's think she's alone with Freddy and Cara revealing herself as a vampire to the two. In the episode, Freddy throws her the Vampire's Breath in a keep away from Nightwing thinking she'll destroy it. Instead she takes some of it for herself and turns around, now sporting fangs.
- The Starscream: In the TV episode, she's shown to be a lowly minion of Nightwing and plots to take the Vampire Breath for herself and overthrow him.
- Undead Child: A young kid vampire.
- What Happened to the Mouse?: In the book, Nightwing and she get into a fight over who will feed on Freddy and Cara. Freddy and Cara decide to use the opportunity to run as they do. Later, Nightwing confronts them again with no mention of what happened to Gwendolyn though it's implied he either killed her or she ran off. In the TV episode, Nightwing turns her into a roach.
