Summer Camp Island: Season 1

Oscar (voiced by Elliott Smith in season 1, Asher Bishop in season 2, and Antonio Raul Corbo in seasons 3–6) and his best friend Hedgehog (voiced by Oona Laurence) arrive at Summer Camp Island with the intent to do typical camp activities, only to discover that the camp counselors are witches and everything on the island is alive. While Hedgehog takes a liking to her new surroundings, Oscar has difficulty adjusting.

Feeling that the monsters are not cute enough, Alice (voiced by Charlyne Yi) turns them into babies with all the campers enjoying their adorable state. Oscar however, elects to turn the monsters back into grownups and he, Hedgehog and Max (voiced by Ramone Hamilton) decide to build a water slide in the hopes that the campers will forget about the monster babies.

Tired of Susie's (voiced by Julia Pott) bossiness and rules, Oscar discovers that he and his fellow campers can earn badges for rewards if they complete certain tasks. Due to the rules, Susie and the witches have no choice, but to adhere to them, though they quickly decide to sabotage the campers' efforts.

When Oscar meets a teenage yeti named Saxophone (voiced by Elijah Wood), he brings him to camp and enjoys his company, showing him the cool things at camp. What Oscar doesn't know however, is that Saxophone will go feral as he slowly enters adulthood.

Oscar pretends to be a talking pair of pajamas named Jimjams (voiced by Bobby Moynihan) to make his friend Pajamas (voiced by Naomi Hansen) happy. But when Oscar gets tired of pretending to be Jimjams, he, Hedgehog, and Max go on an adventure to find the ingredients for a potion that can bring Jimjams to life.

Susie announces the annual talent show, which she wins every year, and makes a bet with Oscar and Hedgehog. They set up a musical act using a piano and half full glasses that form a beautiful melody. However, every time they play they end up causing an unusual earthquake.

Oscar and Hedgehog find themselves lifted into space and to the planet of the aliens and learn that they have no emotions due to one of them having hoarded them all. To avoid having their own emotions drained, Oscar and Hedgehog decide to look for the culprit, but finds that he may be closer than they think.

Oscar and Hedgehog meet Ghost (voiced by Caleb McLaughlin in Season 1 and Xavier Patterson in Season 5 onwards), who has trouble remembering his past and where he came from, so Oscar and Hedgehog set out to find any possible connections. A very anxious Susie gives them a map that leads them to a dangerous swamp.

While at the library, Oscar plays a computer game called Fruit Farmer, but fails to finish it when he is frightened by the vampire at the end. Upon leaving, everyone on the island suddenly takes on roles as characters from the game, forcing Oscar to have to beat it in real life.

Oscar wants to join Hedgehog on the Gold League basketball team, but he is terrible. He promises the basketball (voiced by Luke Lowe) itself to be his best friend and he agrees, suddenly making Oscar the best basketball player. However, Basketball soon becomes possessive and threatens Oscar with revealing his lie.

While attempting a science experiment, Hedgehog and Max get shrunk down and go to a high school for food where they must help photo journalist Cinnamon Raisin Toast (voiced by Alia Shawkat) go to prom with jock Popular Banana Split (voiced by Nat Faxon). Meanwhile, Oscar tries looking for his friends and ends up going feral.

During a softball game, Oscar's pants come down revealing embarrassing underpants. He and Hedgehog learn about a quicksand portal that allows people to travel through time and use it to fix his mistake. They end up causing more problems resulting in them finding solutions for them.

Susie asks Oscar and Hedgehog to throw a "surprise" birthday party for her. While they initially say no, they cave in when they see Susie acting sad. While the party comes together nicely, no one can stand Susie's bossy nature, so everyone says the opposite about how they feel about her.

When Oscar loses his friendship bracelet, the Moon (voiced by Cedric the Entertainer) is emotionally affected and decides to quit his job. At first, Oscar does not seem to mind until Susie deduces that his ignorance is the reason for the Moon leaving. Meanwhile, the Moon decides to take up the harmonica and start a new life.

The monsters try to flee when their Godmonster (voiced by Brenda Vaccaro) announces her return to check on their status as "real monsters". Oscar and Hedgehog help them out by proving that they are legitimately terrifying, but must rescue Oscar when Godmonster kidnaps him to cook him.

When the Sun (voiced by Melanie Lynskey) increases her hotness, Susie agrees to give Oscar the key to the ice cream pantry and gives everyone a flavor called "Peppermint Occasion" resulting in everyone getting powers. Due to being lactose intolerant, Oscar does not get any and the campers try to cheer him up by pretending he is invisible.

While reading a scary story, Pepper's (voiced by Sam Lavagnino in 2 seasons and Julian Edwards in Season 4 onwards) blanket suddenly disappears. Hedgehog takes the lead in solving the case with many of the clues pointing to Oscar who is surprisingly optimistic about the situation. However if the thief is not caught, Oscar will have to go on sailor leave with Susie.

Hedgehog gets bit by a wolf cub (later revealed to be Werewolf Queen, voiced by Lorraine Bracco) after avoiding hitting it with her bike and discovers that she can now transform into a werewolf at the full moon. Susie and the whole camp turn on her and she and Oscar decide to get the Werewolf Queen's fur to cure her, but Hedgehog ends up liking her werewolf form.

When Susie is next to clean the killer whale's teeth, she challenges the campers to a softball game to get out of it. Susie and the witches start using their magic to cheat, angering the campers who insist that Oscar allow them to cheat as well and get back at the witches' unfairness.

Hedgehog's father Jim (voiced by Richard Kind) wants her to attend business camp upsetting Oscar. Out of sympathy, the Moon gives them one of his rocks so that they can stop time and spend as much of their childhood as they can. 3 months later, they encounter an old witch named Ramona (voiced by Lesley Nicol) who warns them of the time creature called the Jabberwock.

Oscar and Hedgehog set out to view the Bupkiss Comet, but the monsters inform the two that a major storm is coming and that it will block their view. The two race to the mountains in an effort to see the comet, but when the storm hogs the top spot to himself, Oscar and Hedgehog take refuge in Ramona's cottage and discover some photos of Susie and Ramona.

When Oscar accidentally destroys a sandwich for Hedgehog's radio show, he sets out to a Sasquatch Monastery to get a new one, but must leave his voice at the door. The Monastery ends up closing and Oscar cannot get his voice back, resulting in him desperately trying to explain his situation to a very angry and annoyed Hedgehog.

Oscar receives a camcorder from his parents, but learn that they think he is making things up about all the magical things on the island. He and Hedgehog decide to make a documentary about all the creatures so that they can send it to them, but Susie does not want to risk the secret of the island out and steals the camcorder.

The campers start telling ghost stories around a campfire despite Oscar's intense fears. Upon hearing the stories, ghosts suddenly appear which results in Oscar beginning to worry about different kinds of ghosts; all of which begin manifesting. Realizing that he must face his fears, Oscar tries to come up with a good ghost to defeat the other ones.

The campers head to Heartforde, the only town on Summer Camp Island that is not magical. Oscar wants to get a normal tube of toothpaste to replace his talkative one, but finds that they are sold out. Now he and Hedgehog must run about the town to help everyone with finding or doing things so that he can get his toothpaste.

Puddle (voiced by Ethan Maher) and the King (voiced by Sam Lavagnino) are getting their castle repainted and decide to stay with Oscar until it is finished. Oscar shows off his hosting abilities, but soon becomes tired and overworked by the aliens' taking up his space. Hedgehog insists that he be honest about his feelings, but Oscar does not want to risk his friendship with them.

On Hedgehog's radio show, Hedgehog gets a call from Skadi (voiced by Betsy Sodaro), a cloud puncher who is having mommy issues. She and Oscar visit her and try to help her get in contact with her mother (voiced by Jane Lynch) to tell her about how many clouds he has punched. When she begins demeaning her, Skadi becomes sad and creates a "momsoon" that begins flooding the island.

Susie and Betsy (voiced by Nikki Castillo) discover that Alice is sick. The last time she caught an illness resulted in a terrible disaster that coated the island. Susie and Betsy are incapable of working closely together, so they put a spell on Oscar and Hedgehog to help them out. However, in their carelessness, Oscar and Hedgehog begin picking up on the witches' habits.

Susie creates a scavenger hunt for the campers to find her lost earrings. When pairing teams, Oscar gets set up with Lucy (voiced by Indie Nameth) and Hedgehog gets set up with Max. With Oscar inconsolable, Lucy decides to train him into being more independent from Hedgehog while Max decides to take Hedgehog to a hidden part of the island she has never visited before.

At Alice's dress-up party the campers are magically turned into their costumes. Unfortunately, this means that the witches are no longer witches and cannot use magic. However, Hedgehog can while Oscar is her mop. She begins abusing her abilities, but soon realizes that being a witch means having responsibilities to uphold on the island.