The protagonist of "Deep Trouble." Billy is a budding undersea explorer on vacation with his uncle, Dr. Deep, and his sister, Sheena. On the trip, he encounters a mermaid who he saves from kidnappers, and later goes on to have many more undersea adventures.
Cloud Cuckoo Lander: In the book's first few paragraphs, he criticizes Sheena for not opening her mind to concepts like the Easter Bunny and Santa Claus.
Friend to All Living Things: He makes fast friends with the mermaid, and claims that when he's a famous undersea explorer, he's going to give the creatures he encounters pet names. H also shows remorse about feeding a school of guppies to Dr. D's pet eel.
Fearless Fool: Not entirely fearless, but when his uncle warns him about sharks in the reef, he replies, "Sharks! Wow!" Later on, he rushes headfirst into a gang of thugs trying to kidnap the mermaid.
Cassandra Truth: Most of the Very Special Guests are not entirely trustworthy of the Morris siblings because they think they might be spies for the Horrors. It turns out however that of course Lizzy and Luke are the trustworthy ones. The twins Jillian and Jackson were unwittingly acting as The Mole for the Menace and attempted to make the Morrises as The Scapegoat. Lizzie realizes they've been trying to fool everyone when she catches Jillian lying.
The Leaders: Of the Very Special Guests in the last two books in the Horrorland series, due to their prior knowledge of the theme park.
Older and Wiser: Although they're only a year older in the HorrorLand series, they return to Horrorland to help out the rest of the kids escape.
Too Dumb to Live: Luke has shades of this in Return to Horrorland since he seems too eager to try out the rides at Horrorland despite the fact that he knows they are potentially lethal and that the Horrors tried to kill him and his family the last time they were there.
Villains and Monsters
Dark Falls Residents
Affably Evil: You wouldn't be able to tell their true nature until it's too late.
Anti-Villain: They feast on living beings to sustain their town's existence.
Almighty Janitor: Compton Dawes, Dark Falls' mild mannered real estate agent, is not only a bloodsucking mutant, but he's also the most responsible for keeping the town alive.
Once a normal young girl staying at "Camp Cold Lake", Della grew tired of the constant safety rules and became homesick. She attempted to swim across the lake to leave camp, but she drowned. Now her lonely spirit roams the camp, desperate for a buddy to take her to the afterlife. She actually tried to leave by going through the woods, but was bitten by a rattlesnake. She made Sarah Maas think she drowned as part of a ploy to lure her into the woods and kill her there.
A living halloween mask, one of several created by a scientist.
Ascended Extra: In The Haunted Mask II, the Mask wasn't featured at all. In the television adaption, the Mask is added to the plot as the main villain, possessing its creator and turning Steve into his minion for the sake of getting to Carly Beth and possessing her again.
Hollywood Acid: Morphs into a large wave of this to kill Skipper. It doesn't work.
Invisibility Cloak: His lair employs this to keep away enemies, as well as to lure a curious Skipper into his trap.
Noodle Incident: No explanation is ever given for how he came to the real world.
Pick on Someone Your Own Size: Toward Skipper. His insane logic is that since this kid knows everything about him while the heroes of his world are complete idiots, he'll make a perfect opponent.Surprisingly enough,he was right.
G-Rated Drug: Although it's not treated like one, a formula that causes massive growth would probably be the ultimate performance enhancer.
Generic Doomsday Villain: This is to be expected, since it's a mindless lifeform, but it's creator, Sarabeth, is a more straightforward example. Other than wanting to keep Evan's aunt as a slave, she has no personality or motivation whatsoever, and is simply in the story to provide an explanation for the ever growing slime.
The Big Bad of the "Night Of The Living Dummy" series of books and currently the one reoccurring character to appear in the most books.
Ascended Extra: Didn't come to life until the very end of Night of the Living Dummy, after the heroes destroyed the main antagonist, Mr. Wood. The sequels obviously focus on Slappy, though he occasionally shares the spotlight with other dummies.
Bad Boss: The way he treats his intended "slaves" should say enough, but he also acts this way to Rocky.