Samhain

Samhain, also known as the origin of Halloween, is a powerful special demon of Hell, who can only rise when summoned by two powerful witches through three blood sacrifices over three days, that last day on the final harvest, Halloween. Once Samhain has risen, he is able to raise ghosts, zombies, and ghouls and unleash them onto the Earth.

History
Samhain is an ancient demon who was worshiped as a god on Halloween by the ancient Celts. When he reigned on Earth on Halloween night, people kept their children in that night. They wore masks to hide from him, carved pumpkins to worship him, and left sweets at their doors to appease him.

Samhain, once summoned by Tracy Davis and Don Harding, possesses the dead body of Don Harding. When he enters the body, the corpse's irises turn milky white, while his pupils stay black, marking him as a different kind of demon than has appeared on the show before. His unique eye color may mean that he is somewhere between the white eyed demons, such as Lilith, and the common black eyed demons.

Personality
Samhain was shown to be cruel, and sadistic, he took pleasure in trapping his hosts students and summoning zombies to devour them, so much so, that he playfully rubbed his hand against the gate as he walked off. He however seemed more interested in simply creating and causing destruction, rather than running it, as rather than consolidating his efforts or powers, he simply passed through the area, causing destruction.

He also showed no loyalty, casually killing Tracy Davis, despite the witch being the one who loved and freed him. He was also shown to be treacherous, and cunning, and had a very violent and ferocious side to his personality. Although willing to use his powers to dispatch attackers, unlike most demons, he was also more than willing to enter physical combat, and try to catch and rip them apart limb from limb with his bare hands.

He was also shown to be quiet, and did not talk much, also when angry, he would start snarling like a wild animal.

Powers and abilities
Samhain is an incredibly powerful demon who displayed multiple rare abilities as well as abilities unique to himself. That his rise was one of the 66 Seals marks Samhain as a special demon; the only other demon who was a seal was Lilith. His rank in the hierarchy of Hell is unknown.


 * Immortality - Although Samhain's exact age was not stated, he is at least over six hundred years old and it is implied that he is thousands of years old.
 * Summoning - According to Sam, Samhain has the ability to summon creatures. Sam also stated that the longer Samhain is free, the more dangerous monsters he would summon, until everything the Winchesters had ever fought would come to him; taken literally, this would include ghosts, zombies, other demons, witches, monsters, deities, and conceivably more.
 * White Light - Samhain has the power to emit a fiery blast of white light that could destroy anything in its path. He was one of only two demons known to have the ability. Other beings who had access to such ability were angels, who were considerably more powerful.
 * Possession - Samhain used the corpse of one of his deceased witch followers as his vessel.
 * Invulnerability - Samhain cannot be killed by conventional methods; he did not die from possessing a body riddled with fatal gunshot wounds, nor did he seem hindered by these injures or even seem to find them inconvenient.
 * Immunity - Samhain is immune to iron, as he was able to close an iron gate and ran his hand over it as he walked away without getting burnt. He was also able to resist Sam's powers better than other demons.
 * Necromancy - Samhain has the power to summon ghosts and bend them to his will, as shown when he had one attack Dean.
 * Reanimation - Similarly, Samhain has the power to turn nearby corpses into zombies and bend them to his will, as shown when he had them attack a group of party-goers.
 * Super strength - Samhain was able to throw Sam across the crypt with great force and minimal effort.

Weaknesses

 * Exorcism - According to Sam, Samhain is susceptible to exorcisms, as he was said to have been exorcised centuries ago. Sam later used his powers to psychically exorcise Samhain.
 * Partial blindness - Unusually for a demon, Samhain's eyesight is impaired, causing him to see the world blurred. If humans are wearing monster masks and costumes, Samhain mistakes them for actual monsters and passes them by without attacking.
 * Demon-killing knife (Possibly) - It is possible that Samhain can be killed by the knife, since he made sure to get rid of it when Sam tried to kill him with it.
 * Sam Winchester - Samhain is vulnerable to Sam's demonic powers. Even when Sam was not drinking Demon Blood, he could use his powers to exorcise Samhain, albeit with immense difficulty for Sam (to the point that Sam got a headache and a nosebleed) and with Samhain almost fighting through it.
 * The First Blade- the First Blade can kill any demon with no exceptions.

Appearances

 * Season 4
 * It's the Great Pumpkin, Sam Winchester

Trivia
Samhain
 * It is possible that, in-universe, Samhain is based on the Celtic legend of Mongfind, a leader who made a false peace with an enemy by giving him poisoned wine. He suspected an assassination, and made Mongfind drink the poisoned wine. Thus she died on 31st October, and the festival, Halloween, came to be named after her. Mongfind lived roughly six hundred years ago, according to legend.
 * Samhain in Supernatural is based on an urban legend that the Ancient Celts prayed to a death deity named Samhain who organized terrible human sacrifices on Halloween. In original Celtic mythology, the deity known as Samhain is associated with cattle and smithery and was a minor deity. Though the Celts did give semi-regular blood sacrifices to even their minor deties.
 * Despite the students wearing costumes in the mausoleum, Samhain was able to see them, even though he couldn't see Sam or Dean properly when they were covered in blood. However, some of them were not wearing masks, which is identified as the key component for tricking him, possibly revealing their humanity to him.
 * In reality, Samhain is the Wiccan holiday on Halloween where the Wiccans celebrate their dead ancestors, loosely based upon an older Celtic holiday of similar name.
 * In this episode the name 'Samhain' was pronounced Sam-Hane, its correct pronunciation is Sow-ann
 * In Bobby Singer's Guide to Hunting, Samhain was described as a Blue-eyed demon.
 * That Samhain's raising was one of the 66 Seals indicates that Samhain already existed by the time Lucifer had been trapped in his cage. The only other demons confirmed to have been made by that time were Lilith, Azazel, Cain and Abaddon.
 * Samhain's White Light ability was the second trait he shared with Lilith, the first one being part of the 600 seals.