Pair of Eyes (1)
In a cell to the southwest of Susie's cell in the Card Castle prison, a pair of eyes can be seen in the darkness. If the party speaks to them, they bemoan what the world is coming to for King to imprison even them: "And I'm only a pair of eyes!".
Trash Can Rudinn (2)
Inside Susie's cell, there is a Rudinn that Susie "invited to the trash can." If spoken to, they express how much they like the trash can, and that they want to invite their friends.
Circus Wagons (3)
On the eastern end of the prison level, beyond the elevator, there are four brightly colored wheeled circus wagons with tails and smiling lion faces. Each wagon is a cage which contains prisoners, but their lion heads can talk to the party as well. The leftmost wagon contains the Three Kings; the rightmost contains a number of animals; while the middle two contain, respectively, a Jigsawry arrested for illegally making a puzzle and a Rudinn that refused to fight the party.
The leftmost and the rightmost wagon appear in the Throne Room after the party defeats King, again with unique dialogue.
Three Kings (4)
The three other Kings who were captured by King and Knight are imprisoned in the leftmost circus wagon in the prison. Unlike King, they do not have unique designs, save for the Diamond King; the King of Clubs is a Clover-like Darkner, and the King of Hearts is a Hathy. The King of Diamonds is the sole exception, being lime green with a cape reminiscent of King's own cape, as well as multiple tentacles as opposed to the singular ones Rudinns have. The Clover and Hathy kings have no dialogue, but the Diamond King introduces the Kings to the party and worries about his treasure now that King has taken over. He does not seem concerned for the fate of the party's world.
After King is defeated by being overthrown, the three Kings, still in their wagon cage, appear in the Throne Room. The Diamond King continues to beg for freedom, but becomes contented when he realizes that his treasure is unharmed.
Circus Animals (5)
A bunch of brown animals, resembling animal crackers, are crammed into one cage and lament the presence of the other prisoners.
Once King is defeated, the animal cage appears in the Throne Room. If addressed, the animals explain that the other prisoners are now welcome to dwell in their cages if they agree to wear animal ears and noses.
Starwalker (6)
If spoken to in the Forest, Starwalker appears again in the Castle's dungeon, this time remarking how the jail is pissing him off.
???? (7)
A diamond-shaped NPC who appears in the crowd during the ending where King is overthrown.