Prison Keeper

The Prison Keeper is a Heartless boss in Kingdom Hearts II. It appears in Halloween Town on the first visit.

After Maleficent resurrects Oogie Boogie, she left Lock, Shock and Barrel behind to deal with Sora and Jack Skellington. She summons a Heartless called the Prison Keeper. Lock, Shock and Barrel sit in the cage at its base. After a while it swallows one of the three, and its attacks depend on the child: Near the end of the fight, it swallowed all three and used a mixture of attacks: it shot fireballs from its eyes, slashed, and spun.
 * Shock: The Prison Keeper will spin its arms around, rising up and then falling down while spinning around the arena, firing lasers. Its arms glow a dark yellow.
 * Lock: It will shoot large fireballs out of its mouth and hands from a distance. Its arms glow red.
 * Barrel: It will use a powerful biting attack on just Sora and slash madly. Its arms glow green.

Sora defeats the Heartless and Lock, Shock and Barrel reveal Maleficent's plot.

Kingdom Hearts II
A Heartless called forth in Halloween Town by Maleficent to get revenge on Sora.

It held Lock, Shock, and Barrel captive while dealing various elemental attacks.

Trivia

 * The Prison Keeper is the only Heartless boss ever to appear in Halloween Town in the series, except for Chimera in Kingdom Hearts: Final Mix.
 * The Prison Keeper is the first boss to have over 1,000 health in Kingdom Hearts II.
 * The Prison keeper is the only other boss, the first being the Pot Centipede, to have no cutscene showing its demise.