Chernabog is the demonic denizen of Bald Mountain, that appears as a boss at the End of the World in Kingdom Hearts, and in Symphony of Sorcery in Kingdom Hearts 3D: Dream Drop Distance. He originally appeared in Disney's Fantasia, in the segment set to "Night on Bald Mountain".
The Japanese version of the game uses "Squirming Evil", the track used for most Disney Antagonist battles. However, in the international version of Kingdom Hearts, as well as in Kingdom Hearts Final Mix and Kingdom Hearts 3D: Dream Drop Distance, the background music for the battle with Chernabog is an arrangement of "Night on Bald Mountain", renamed "A Night on the Bare Mountain."
Chernabog is one of only eight enemies who do not have entries in Jiminy's Journal. The others are AntiSora, Bit Sniper, the Cave of Wonders Guardian, Shadow Sora, the Crank Tower, the Shark, and the World of Chaos.
 Kingdom Hearts
Chernabog survived the destruction of his homeworld, Symphony of Sorcery, and wound up at the End of the World.
While fighting through legions of Heartless on their way to confront Ansem, Sora, Donald, and Goofy stumble upon Chernabog at the remnants of Bald Mountain. He awakens and promptly attacks the trio, but is defeated in an explosion of fire after a battle, revealing the passageway deeper into the mountain.
 Kingdom Hearts II
Chernabog makes a brief appearance in one of Roxas's dreams.
 Kingdom Hearts 3D: Dream Drop Distance
Chernabog appears in the world Symphony of Sorcery, as a Dive sequence boss fight. After Riku confronts Young Xehanort and talks with him for a brief while, Xehanort summons Chernabog from the volcano behind him to fight Riku.
 Other appearances
 Kingdom Hearts Re:coded
Chernabog appears as a Scratch Card icon on the Villains Card.
Chernabog is a gigantic, muscular, humanoid demon. His skin is entirely colored black, and he is so large that Sora is roughly the size of his head. His head sports two curved horns, he has four fangs in his mouth, and his eyes are a glowing yellow. He has enormous, black, bat-like wings, and his wingspan is larger than he is tall. Chernabog is always seen trapped from the knees-down in a volcano.
Chernabog has many frightening powers at his disposal. His main ability is to control fire, and uses it in various ways such as breathing fire or shooting fireballs from his hands. He can also cause the volcano he resides in to erupt with tremendous force, flap his huge wings to create a gale to blow opponents away, and, when in desperate need, summon six orbs of light to attack opponents.
 Kingdom Hearts
Although his attacks are few, they are very upscale and dangerous to the health bar. The most powerful attack is when he looks as though he is bent over, apparently hurt, but then rises triumphantly, causing the volcano to erupt violently. This attack gets more powerful later in the battle. Another attack would be when he consistently breathes fire, either from left to right, or right to left. When he begins to lose health, he will use variants of Aero to knock the party far away from him, at which point he will send out beams of light similar to the ones Ansem casts from his World of Chaos form.
A good way to avoid the first one is to quickly fly away, and press to signal to Donald and Goofy to follow Sora, so that they will not perish either. The second can be avoided by simply flying behind his head, and merely waiting for him to stop breathing fire. Also, now would be a good time to attack from the back of his skull. The third cannot be avoided, but the fourth can be difficultly maneuvered past.
As Chernabog is fought while in flight, summons are not available to the party, which can be a serious hindrance. However Sora can get around this by landing on his shoulder or the summit of the mountain. Summoning Tinker Bell can be a tide turning advantage. Also, using Aeroga can help a great deal, as it helps decrease the damage dealt. You gain the Superglide ability for winning the battle.
 Kingdom Hearts 3D: Dream Drop Distance
Instead of maneuvering around Chernabog, the fight uses the format of Dive Mode. Riku must use the Diving Strike ability to attack Chernabog a total of three times to defeat him, however reaching him is not easy. Riku must avoid the fireballs the demon throws and the pillars of fire that errupt from below. These can be avoided by either flying around them or using Dodging Deflect, the latter technique grants temporary invincibility. Each time Riku successfully damages Chernabog, the demon will knock him back further down the valley and it will take longer to reach him.
Chernabog's most dangerous attack is to summon ghosts that will attempt to grab Riku. These ghosts slowly drain Riku's health and must be shaken off by performing a Dodging Deflect. There are two varities of ghosts, the white versions take longer to shake off. A risky but effective method of removing the ghosts is to perform a Dodging Deflect into a fire pillar. If timed successfully, Riku will remove the ghosts but not take damage.
Chernabog first appeared in Walt Disney's Fantasia, during the Night on Bald Mountain segment, in which he erupts from the mountain in the same way as in the game. Chernabog awakens on top of Bald Mountain on Walpurgis Night, and uses his dark powers to raise ghosts, skeletons, demons, witches, harpies, goblins, and zombies from a nearby town. He summons fire and lava, and makes the wretches in his control dance and fly around, before he destroys them. However, the Angelus bells suddenly begin ringing, heralding sunrise, driving Chernabog and his slaves back into hiding, as a line of monks proceeds through the forest and a ruined cathedral to the sounds of the "Ave Maria".
His name is taken from the Slavic deity Crnobog, whose name means "black god". However, Disney designed him with Satan in mind. His Japanese name, "Demon of Fantasia", references his role in Fantasia, the Disney film he first appeared in.