Jack is a sensitive boy struggling to accept significant changes in his daily life, primarily his parents' sudden divorce and his mother's new marriage. He relies heavily on his beloved childhood toy, Dur Pig, as his primary confidant and source of emotional stability. When his step-sister destroys the toy, Jack's intense love for his friend drives him to venture into the magical Land of the Lost to find him.

Dur Pig, affectionately known as DP, is Jack's favorite stuffed animal. Worn-out, grayish, and sporting replacement button eyes sewn on by Jack's mother, DP has been Jack's constant companion through years of childhood. He serves as Jack's primary comfort and silent listener during the tumultuous changes in the boy's family life, making his sudden disappearance devastating.

The Christmas Pig is a brand-new stuffed animal purchased by Jack's grandparents to replace the missing Dur Pig. Brought to life by the magic of Christmas Eve, he is a clever and opinionated toy who understands the depth of Jack's grief. Despite Jack's initial hostility, the new toy bravely offers to guide the boy into the dangerous Land of the Lost to search for his missing friend.

Holly is a talented teen gymnast who initially shows kindness to Jack at his new school. As she copes with her own parents' divorce and learns her father is marrying Jack's mother, her behavior shifts dramatically. She becomes antagonistic and channels her hidden pain into bullying Jack, a conflict that ultimately leads to the tragic loss of Dur Pig on the motorway.

The Loser is the fearsome and tyrannical monster who rules the Land of the Lost. He preys on lost, unwanted, and rule-breaking Things, devouring them to build his own horrific armor from their broken pieces. The constant threat of his hunting expeditions casts a dark shadow over the territory, forcing the lost items to live in strict obedience and fear.

Jack's mother is a hardworking nurse who does her best to support her son through the aftermath of her divorce. She loves Jack deeply and carefully repairs his toys, but she remains largely unaware of the extent of his inner turmoil regarding her new relationship. She attempts to create a happy, blended family environment while managing her own major life transitions.

Jack's biological father moves abroad following a sudden divorce from Mum. Though he keeps in touch with Jack, his physical absence leaves a significant void in Jack's life and acts as the catalyst for the boy's heavy reliance on his stuffed pig for emotional support.

Brendan is Mum's new boyfriend and eventual husband. He is an affable man who tries to build a relationship with his new stepson while managing his own complicated dynamic with his teenage daughter, Holly. His integration into Jack's household represents a major adjustment for the young boy.

Gran and Grandpa are Jack's supportive grandparents who help care for him while his mother works. They try to maintain peace during tense family holidays and frequently attempt to mediate between Jack and Holly. Well-meaning but sometimes misunderstanding Jack's deep attachments, they are the ones who purchase the new toy pig to replace the lost one.

Compass is a broken directional tool lost by a hiker in the forest. Condemned to the desolate Wastes of the Unlamented, she maintains a cheerful, brave disposition and a keen thirst for adventure. She willingly puts herself at risk to help guide desperate travelers through the dangerous territories of the Land of the Lost.

Poem is a personified piece of written verse who speaks entirely in rhyme. Despite facing her own gradual decline in relevance as her owner forgets her, she uses her resources to bravely shelter surplus items from enforcers, operating a secret network to aid fugitives.

Hope is a powerful, glowing figure with majestic feathered wings who resides in the City of the Missed. Lost by a political prisoner in the human world, she awaits the day her owner can find her again. She embodies resilience and proves to be a formidable ally against oppressive forces.

Happiness is a bright, glowing entity representing a lost human emotion. Cheerful and benevolent, she uses her radiant light to assist others in the City of the Missed, providing crucial distractions and support for those trying to evade capture.

Broken Angel is a fragile Christmas ornament originally crafted by Jack from a toilet paper roll. After being destroyed by the family dog and discarded, she ends up navigating the desolate Wastes. Despite her grim surroundings, she forms supportive bonds with other discarded toys to endure the harsh environment.

Blue Bunny is a cheaply made, unwanted fairground prize who was discarded out a window as a joke. Now wandering the Wastes of the Unlamented, the gloomy but loyal toy finds solace in his friendship with the Broken Angel, illustrating the camaraderie that forms among forgotten things.

Power is the domineering and arrogant king of the City of the Missed. A human trait lost by his owner, he attempts to rule his domain with an iron fist, demanding constant flattery from his subjects and viewing outsiders as commodities to be traded for his own political gain.

Bullyboss is a physical manifestation of a discarded human behavior, specifically taking the form of a mean-looking fist representing Holly's decision to stop mistreating her stepbrother. He roams the Land of the Lost with other forsaken bad habits, hoping his owner will one day reclaim him.

Addie is a bossy, officious address book living in the town of Bother-It's-Gone. She enjoys lecturing others and adhering strictly to the rules of her new environment, making her a bothersome presence to the more rebellious inhabitants of the town.

Sheriff Specs is a pair of spectacles acting as the cheerful but vigilant leader of the Disposables area in the Land of the Lost. Tasked with maintaining order among the recently lost items, he keeps a sharp eye out for anything that does not belong in his jurisdiction.

Mayor Cheese Grater is the mean-spirited municipal leader of the town of Bother-It's-Gone. Desperate to appease higher authorities and maintain his own standing, he actively hunts down rule-breakers and outsiders who wander into his town.