The kids and Bat Pat are going on a school field trip to spend the night in a castle. Martin can't wait to sleep in a historical landmark, but his enthusiasm immediately disappears when he realises the castle is really a very creepy place. As the gang spends the day in the castle, they come to suspect the place may be haunted.
After numerous sightings of a furry beast in the Whispering Forest, "supernatural expert" Ivan Templeton is determined to catch the "menace" to make a name for himself. Hoping to prevent such a fate, the kids and Bat Pat search for the creature in the Whispering Forest and it turns out to be a werewolf...hanging out and dancing to music!? The werewolf is captured by Ivan.
A tremendous storm damages the secret bakery of the legendary Corky the Cookie Elf, the little creature who bakes the world's greatest cookies: Elfies. Corky vows to never make the delicious treats again… because he needs a new cookie maker. Leo loves Elfies and can't stand the idea that they might never be made again!
The kids' school is being haunted by a ghost named Walter Winthrop III. Although he's an adult, it seems that Walter never graduated from school because he could never focus in class and failed his final exam. Walter wants to take classes to help him finally pass his final exam, so Martin sets up a ghost school in his attic to teach Walter so he can graduate.
Something is flying around Fogville at night and scaring people who happen to be out after sundown and it seems to be a bat! Bat Pat leads the kids on a mission to find the wayward bat and teach him some manners. The trail leads Bat Pat and the kids to a haunted house where they discover Carl the vampire.
Everyone in Fogville is having bad dreams - dreams that appear to belong to other people. After consulting with Capistrano Fog, the kids and Bat Pat are able to enter the dreams where they meet the mystical creature responsible for making people dream. He's called the Duke of Dreams and the gang tells him about his mistaken dream mix-ups.
A Ghost bike is riding around Fogville and people are accusing Martin of being behind the odd events as they claim he's the one they see riding the bike. The kids and Bat Pat discover the erratic bike rider is none other than their ancestor Uncle Martinus, who looks a lot like an older Martin in old-timey clothes!
Phil Mooney wished that someone would help with the trash, and he ended up inside the can at the curb. Did his wish come true? Leo wishes for a high-tech skateboard and it appears almost like magic. Sure, it's a little handmade and doesn't quite work like the real thing, but his wish did come true, right?
Something strange is lurking in the bushes at Fogville Park and swiping items from picnickers. When the creature later tries to swipe a bowl of popcorn from Leo and Bat Pat, the gang realises it's a leprechaun named Seamus. Seamus is the world's most unlucky leprechaun and he's searching for his lost pot of gold.
Something spooky comes into Rex and Melissa's rooms while they're sleeping and makes horrible noises. Rebecca notices an interesting part of the mystery: Both of them had recently lost a tooth. Rebecca fakes Martin losing a tooth to get the creature to visit their house, but the "beast" is in fact… the Tooth Fairy!
The kids and Bat Pat discover a cute stray puppy and take it home with them. The puppy loves to play fetch, but the first time Leo is alone with the puppy, it barks and its head morphs into a terrifying demon dog. Leo tries desperately to make the puppy bark in front of the others to show them the transformation, but the puppy never does.
While camping at Camp Sunny View, Bat Pat and the kids hear a creepy rattling sound coming from the forest. They realize the creepy rattling is Bones the Skeleton's bones rattling together because he's so cold! They take Bones to stay with Natty, where they solve his cold problem by putting Bones the Skeleton inside a stuffed scarecrow.
Summer has officially started and the people of Fogville are hitting the beach, including the Silver family and Bat Pat. But their plans are derailed when a series of huge "potholes" in the street have jammed the traffic. The kids and Bat Pat eventually realise that the potholes are really footprints caused by a T-Rex that had been frozen in a block of ice.
Numerous rainbows appear over the Whispering Forest and turn it into a bright and happy place. The creatures of the Whispering Forest hate bright and happy, so they began fleeing into Fogville and even take over Natty's barn. But worst of all, the bright rainbows have made Martin's favorite Goth musician, Gothra, turn happy and sing happy songs.
Strange noises - and the occasional blast of fire - are coming from the Whispering Forest. But the Silvers don't know that yet because Elisabeth has the family taste-testing her chili for the Fogville Chili Cookoff. Unfortunately, it's not spicy enough. Leo inadvertently volunteers to find a super spicy pepper to provide some tasty heat.
Something is stealing garden gnomes from the gardens of Fogville! The kids and Bat Pat discover the thief is a real gnome! The gnome, whose name is Fudwick, isn't very bright and he's convinced that all the garden gnome ornaments in Fogville are real gnomes turned into statues by the people of Fogville.
When strange things start to happen with the basketballs at school, Rebecca thinks there's a ball revolt going on. But when the kids and Bat Pat encounter some small green creatures by the school equipment locker, they follow them into the Whispering Forest and realize it's a group of goblins who are trying to "borrow" a basketball.
On a sleepover at the Silvers, their friend Phil's sleep is disturbed when he discovers a monster under the bed. The monster known as Melvin just needs a place to sleep, and the Silvers offer him a temporary home. But his first night is a disaster for Martin - Melvin's a restless sleeper who tosses and turns, sleepwalks and gets up in the middle of the night for water.
There's a new teacher in Martin's class. Martin's a bit taken by her, but there's something odd about Ms. Brittle: she's very nervous and jumpy and is convinced a creature is following her. Rebecca thinks she might be cursed, but the kids come to realise that a creature is indeed following her… because he wants to ask her out on a date!
After several shops in Fogville are ruined the night before Valentine's Day, Rebecca is convinced there's a Valentine's Day creature that wants to ruin Valentine's Day. But it ends up being an ogre named Grundulla that wants a makeover for her big Valentine's Day date with an ogre from across the swamp. Joined by Natty, the kids and Bat Pat do their best to give Grundulla and awesome makeover.
After a mysterious creature takes a shower at the Mayor's house, the kids and Bat Pat follow the clues to Dreary Swamp and discover the culprit is a swamp monster! He's been extra smelly lately. He's in a book club with a goblin and an ogre, but they can't stand to be near him anymore! He's been trying to find something to find a way to smell better.
Melody Forte encounters a big, hairy creature lurking outside her window while watching the TV show "Cha Cha with the Stars." When the hairy creature shows up at Martin's school dance, the kids and Bat Pat realise it's Bigfoot. When they find Bigfoot in the Whispering Forest, they discover he's been appearing in Fogville because he wants to learn how to dance.
A reality TV show host, Tiger Leatherheart, discovers a mysterious and fierce creature on Black Skull Island while filming his show. After Tiger vows to capture the creature, Rebecca is determined to save the creature from Tiger. The kids and Bat Pat travel to Black Skull Island and, under the guise of "helping" Tiger find the creature, they set off to find the creature before Tiger does.
Everyone's peaceful Halloween is disturbed by a galloping horseman riding through Fogville terrorizing trick-or-treaters. Rebecca's determined to solve the mystery and discovers that the rider is the infamous "Headless Horace" who legend says rides through town in search of souls to steal. But the kids and Bat Pat discover that Horace isn't looking for souls to steal.
A witch flying on a broom is terrorising Fogville! Bat Pat and the kids track the witch to her creepy cottage in the Whispering Forest and discover the witch doesn't mean to scare anyone she's just a terrible flyer and can't control her broom. Martin helps the witch into the modern age by designing flight stabilisers for her broom.