Nightmare King

"You think you can hide? I know exactly where you are."

- The Nightmare King

The Nightmare King is the ruler of the dreaded Nightmare Land and the main antagonist of Little Nemo: Adventures in Slumberland. He is also a new villain of Sailor Moon. He was voiced by both Tarō Ishida in the Japanese adaption and Bill Martin in the English adaption.

Biography
The origins and history of the Nightmare King are unknown, but he is apparently the embodiment of nightmares, he rules over Nightmare Land, a dark world which represents all the fear and darkness of the world's nightmares. At some point in the past, he was imprisoned beneath Slumberland by his enemy King Morpheus, he was lock behind a giant door which all residents of Slumberland were forbidden to open lest the evil king be set free again.

Original version
During the movie, Morpheus summons a young boy named Nemo to Slumberland to be his heir and playmate to his lonely daughter, Princess Camille. Nemo is a boy who suffers from constant nightmares and while his parents say the reason is because of his habit of sneaking pies late at night, it's strongly hinted several times that the Nightmare King may, in fact, be the one responsible for his endless nightmares.

When Nemo is brought to Slumberland, the Nightmare King is released after Nemo unlocked the door that Morpheus warned him not to open. Nemo rushes back to Morpheus' castle in time for his coronation ceremony, where Nemo is handed the royal scepter, the only thing capable of defending Slumberland in the event of the Nightmare King's return. In the middle of a dance session between Morpheus and Professor Genius, the Nightmare King reaches the castle and steals Morpheus away. As the partygoers search for a scapegoat, Flip reveals Nemo to be responsible for the Nightmare King's escape.

Nemo awakens in his home, which floods with seawater and ejects him into the ocean. Genius discovers Nemo and tells him not to blame himself for all that has happened. When the two return to Slumberland, Flip reveals that he has a map to Nightmare Land, where Morpheus is currently being held. Nemo, Camille, and Flip set off in a tugboat in search of Morpheus.

They are soon sucked into a whirlpool and find themselves in the monster-infested Nightmare Land. The trio comes across a group of shapeshifting goblins who wish to aid in the quest to find Morpheus. The Nightmare King sends a flock of giant bats creatures to seize the rescue party. Nemo attempts to use the scepter, but once again awakens back in his bed. The goblins appear in Nemo's room and the group travels together to the Nightmare Castle within the Nightmare Land by flying through a hole in the sky called the "Gate of Wind".

At his castle the Nightmare King is informed that Nemo has been terminated but his giant manta ray soon informs him that Nemo is in the castle with the sceptor, enraged the Nightmare King absorbs his army due to their failiure. He then sucks Nemo and his friends into his lair where he demands possession of the scepter. When Nemo fails to reply, the King reveals the Professor, Princess Camille, and Flip whom he has imprisoned in giant reliquaries and begins to taunt the boy. When even this fails, he tops it off by imprisoning King Morpheus in a reliquary of his own right before Nemo's eyes.

Nemo tries to save him but the Nightmare King has his giant sting ray try to kill him but Nemo soon destroys it with the scepter. He again asks Nemo to give him the sceptre because, after all, Nemo cannot even remember the words necessary to use it. Nemo refuses and valiantly uses the scepter to fight off the Nightmare King by destroying his hand. Now enraged, the Nightmare King tries to absorb Nemo and his friends and finish them for good. In a last desperate effort, Nemo just barely manages to say the full incantation to the scepter unleashing it's full power to destroy the Nightmare King once and for all, albiet at the cost of his own life, ending his evil reign along with Nemo's own nightmares.

Shortly afterwards, all the King's spells are lifted freeing everyone and Nemo is quickly revived by King Morpheus who forgives him for breaking his promise. Sometime later, Slumberland celebrates the fall of the Nightmare Kingdom. After which Nemo returns home and once more awakens in his room, this time peacefully, now forever free from his endless nightmares due to the Nightmare King's destruction.

Remake version
The Nightmare King's role is remains similar to the original version. During the movie, Morpheus summons a young boy named Nemo, Usagi, Mamoru, Sakura, Ami, Rei, Makoto, Minako, Syaoran and Meiling, who came from the future, to Slumberland to be his heir and playmate to his lonely daughter, Princess Camille. Nemo is a boy who suffers from constant nightmares and while his parents say the reason is because of his habit of sneaking pies late at night, it's strongly hinted several times that the Nightmare King may, in fact, be the one responsible for his endless nightmares. Dark Mercury, an evil doppelganger of Sailor Mercury, was created from Ami's nightmares by the Nightmare King.

When Nemo is brought to Slumberland, the Nightmare King is released after Nemo unlocked the door that Morpheus warned him not to open. Nemo rushes back to Morpheus' castle in time for his coronation ceremony, where Nemo is handed the royal scepter, the only thing capable of defending Slumberland in the event of the Nightmare King's return. Prince Endymion slipped into a ball in disguise, in order to meet with Princess Serenity. He told her that since war between Queen Beryl, a woman possessing the power of the evil entity Queen Metalia and Queen Serenity was about to break out 10,000 years ago on the Moon, he couldn't allow his identity to be known, but passed on a warning about the Nightmare King and his plans. If Nemo did nothing, he said, Dreamland would be destroyed; when he asked Princess Serenity to help him she agreed, and the two of them embraced as tears leaked from Serenity's eyes. In the middle of a dance session between Morpheus and Professor Genius, the Nightmare King reaches the castle and steals Morpheus away. As the partygoers search for a scapegoat, Flip reveals Nemo to be responsible for the Nightmare King's escape.

Nemo awakens in his home, which floods with seawater and ejects him into the ocean. Genius discovers Nemo and tells him not to blame himself for all that has happened. When the two return to Slumberland, Flip reveals that he has a map to Nightmare Land, where Morpheus is currently being held. Usagi and her friends transform into the Sailor Scouts, revealing their secret identities to Nemo, Camille, Flip, and Genius. Sailor Moon, Sailor Mercury, Sailor Mars, Sailor Jupiter, Sailor Venus, Nemo, Camille, and Flip set off in a tugboat in search of Morpheus.

They are soon sucked into a whirlpool and find themselves in the monster-infested Nightmare Land. The trio comes across a group of shapeshifting goblins who wish to aid in the quest to find Morpheus. The Nightmare King sends a flock of giant bats creatures to seize the rescue party and Dark Mercury to defeat Sailor Moon. Sailor Moon, Sailor Mercury and Sailor Mars defeat Dark Mercury with Moon Bubble Fire. The Sailor Scouts distract the King's army, allowing Tuxedo Mask, Sakura, Syaoran, and Meilin to enter the Nightmare Castle. Nemo attempts to use the scepter, but once again awakens back in his bed, luckily for the Sailor Scouts, they still have their transformations during Nemo's awakening. The goblins appear in Nemo's room and the group travels together to the Nightmare Castle within the Nightmare Land by flying through a hole in the sky called the "Gate of Wind".

At his castle, the Nightmare King is informed that Nemo has been terminated expect the Sailor Scouts, but his giant manta ray soon informs him that Sailor Moon and Nemo are in the castle with the sceptor, enraged the Nightmare King absorbs his army due to their failure. He then sucks the Sailor Scouts, Nemo and his friends into his lair where he demands possession of the scepter. When Nemo fails to reply (Luna warned him that if he used the power of the scepter it would kill him), the King reveals the Professor, Princess Camille, and Flip whom he has imprisoned in giant reliquaries and begins to taunt the boy, angering Sailor Moon. When even this fails, he tops it off by imprisoning King Morpheus in a reliquary of his own right before Nemo's eyes.

Nemo tries to save him but the Nightmare King has his giant sting ray try to kill him, but Nemo and Sailor Moon join forces and soon destroy it with the scepter and Moon Tiara Action. He again asks Nemo to give him the sceptre because, after all, Nemo cannot even remember the words necessary to use it. Nemo refuses and Sailor Moon looks at the Nightmare King with new determination in her eyes, telling him that she is the protector of Slumberland and the Dream World and his worst nightmare. She calls out Moon Healing Escalation, and the power of the Silver Crystal falls on the Nightmare King. He resists against the power of Sailor Moon, power so strong that she sparkles with it. Nemo valiantly uses the scepter to fight off the Nightmare King by destroying his hand. Now enraged, the Nightmare King tries to absorb Sailor Moon, Nemo, Sakura, Tuxedo Mask, the Sailor Scouts, and their friends and finish them all for good. The four Sailor Scouts use all of their power to weaken the Nightmare King. This has no effect on the Nightmare King and Sailor Moon uses the Silver Crystal to transform into Princess Serenity in order to help Nemo. In a last desperate effort, Nemo barely manages to say the full incantation to the scepter unleashing it's full power, along with Princess Serenity and the Sailor Scouts use Moon Prism Power to destroy the Nightmare King once and for all, albeit at the cost of his own life, ending his evil reign along with Nemo's own nightmares.

Shortly afterwards, all the King's spells are lifted freeing everyone and Nemo is quickly revived by Sailor Moon and King Morpheus who forgives him for breaking his promise. Sometime later, Slumberland celebrates the fall of the Nightmare Kingdom. After which Nemo returns home and once more awakens in his room, this time peacefully, now forever free from his endless nightmares due to the Nightmare King's destruction.

Videogame appearance
The Nightmare King appears as the primary antagonist and final boss of both the 1990 Nintendo videogame Little Nemo: Dream Master and the 1990 Capcom arcade game Nemo. In both games he sends both his army of nightmarish denizens of the Nightmare Kingdom and evil boss monsters to invade Sumberland and to destroy Nemo but Nemo took on and beaten his minions and than defeated the Nightmare King himself.

Trivia

 * The Nightmare King bares strong resemblance to Chernabog.
 * He also slightly resembles Black Doom from Shadow the Hedgehog
 * The Nightmare King is similar to Lord Nightmare