The Hero
A bold monster scout who is a rebel by nature.
- Kid Hero: A young delinquent turned monster master.
- Mystical White Hair: Has pure white hair and is a natural monster scout.
The Incarnus
A mysterious and powerful monster who tags along with the Hero.
- The Chosen One: Interestingly, is this one rather than the Hero himself. The Incarnus was born to prevent a great catastrophe and it is up to the Hero to bring him around to different shrines across the Green Bays so that he is strong enough to challenge whatever evil rises.
- Defrosting Ice King: Is mostly dismissive of the hero (and humanity as whole) at first, remarking how he is only his monster out of convenience. Eventually though they grow a close bond and the Incarnus decides to become a permanent member of the Hero's team.
Solitaire
A tomboyish girl whom the Hero and Incarnus bump into quite a bit.
- Arrogant Kung-Fu Guy: Is overall a super competitive and vain girl who fancies herself the best monster scout in the world and can back up most of her bragging with monster teams consisting of Atlas, Metal Kaiser Slime, and Mumboh-Jumboe or even the Triumgorate in Joker 2 Professional.
- Cleavage Window: Her dress in Joker 2 shows off her cleavage, since this is after the events of Joker 1.
- Embarrassing First Name: Solitaire is a nickname she made for herself, since she doesn't like her real name, Ginny Rummy.
- Nice Job Breaking It, Hero: Attacking the Hero and his Incarnus companion not only gets her disqualified from the Monster Scout Tournament, but also allows Dr. Snap to corrupt Incarnus into the Ace of Spades with the Darknoium Orb after the Hero just won the tournament and was about to get the Mark prize.
- The Rival: And unlike Kameha, she can actually back up her threats and boasting.
- She's All Grown Up: Appears again in later games as a grown woman and she is strikingly beautiful.
- Sore Loser: She never takes defeat well and almost always throws a small tantrum after losing.
Madame Rummy
An extremely rich and enormously fat aristocrat who lives on Palaish Isle and is the owner of the Metal Menagerie on it. She is also Solitaire's mother.
- Gonk: An absolutely hideous woman, you would be forgiven for thinking she was a monster rather than a human.
- I Was Quite the Looker: Some portraits around her house imply she used to be beautiful, as well as greatly resembling her daughter.
Warden Trump
The leader of the shadowy organization known as CELL.
- Luke, I Am Your Father: An amusing inverted example. The Hero is aware Trump is his father from the beginning, but no one else ever finds out despite the obvious clues.
- Younger Than They Look: He looks like an old man, especially with his white hair, but is in fact middle-aged and he is a platinum blonde. His son inherited his hair color.
Dr. Snap
An accomplished scientist, champion monster scout, and current commissioner of the Monster Scout Organization. Underneath his kindness, however, lies a darker side to his studies...
- Flunky Boss: His Snapped form is aided by a Demon-at-Arms and a Tortured Soul during the final battle.
- One-Winged Angel: Snap gets infected with dark matter from his Darknoium Orb running haywire and turns into a gross walking zombie hand monster, known as Dr. Snapped. Unlike other villains who hate their final forms, Snap loves it since he discovered that dark matter can turn humans into monsters and vows to share it with the whole world.
- Pet the Dog: He helps the Hero heal Incarnus after its battle with the Orc.
- Villain Has a Point: Declaring Solitare disqualified from the Monster Scout Tournament may have made her more angry at the Hero for getting an easy win, but he was right to do so, since attacking a Monster Scout's monster is against the rules.
- Villain with Good Publicity: Dr. Snap is a very well respected monster scout within the Organization, even when he's conducting experiments on monsters and the dark matter. Even after his true colors are revealed, he's still seen as that very person, due to the Monster Scout Organization not wanting to whip the public in a frenzy with the truth.
- Visionary Villain: Dr. Snap mentions several times throughout the game of wanting to make a paradise for monsters, ala Iris. Even when infected with dark matter, it doesn't dent his dream in the slightest, since he can turn humans into monsters, having witnessed this discovery himself. This even continues into Joker 3, where despite being defeated by Incarnus and the Hero, he vows to make all the monsters be BREAK monsters, regardless of their say in the matter.
