Serpens Clavem

The Serpens Clavem was an ancient relic and a powerful vessel of pure evil. The key had the power to open the door to Asgard via the portal located in the Catacombs under Fair Haven. The key was destroyed by Joanna Beauchamp in Snake Eyes.

Appearance
The Serpens Clavem was made of gold, it's coiled body was detailed with scales and it's eyes held two blood red stones, which, when a person looks into them they were immediately entranced, allowing the snake to attack them. The base of the tail is shaped like a key. When the snake latched onto Wendy, its body wrapped tightly around her arm, its fangs having sunk into her arm. It almost looked like a bracelet.

History
The Key was forged thousands of years ago and originated from Asgard, at some point the Key took control of King Nikolaus and killed everything good inside of him. After the rebellion, Joanna stole the Key with the help of one of the King's guards and used it to escape Asgard with her family. Once Frederick had escaped from Asgard, Joanna gave him the Key to seal the portal. Instead of sealing the portal, Frederick threw the Key into it which allowed King Nikolaus to obtain it once again. The King then entered the Mortal Realm and cursed his family for betraying him. Angered by what he had done to them, Wendy cut off his arm as revenge, thus separating the Key from him. After Frederick and the King returned to Asgard, Wendy used the key to seal the portal. Some time later, the Key was obtained by Archibald Browning. Joanna and Wendy stole the key from Archibald in order to destroy it, but however rather than destroying it, Joanna decided to bury it in the garden of her home in hopes that one day she might use it to go back to Asgard and see her son, Frederick, who she left behind.

Possession
Possession only happens by looking into the red eyes of the Serpent. Wendy stared into the Key so it entranced her in the kitchen of the Beauchamp Family Home, by luring her with voices calling her name and it then attacked her, coiling tightly around her arm then sinking it's fangs into her wrist. The snake then pumped its venom into her veins causing her to become the snake's vessel and it took possession of her body. After the venom had reached her head, her pupils turned pitch-black. A victim possessed by the snake will display greater powers (due to it's dark magic), like speed and enhanced strength. When Wendy was possessed by the Key she was also able to leap to high distances. The snake's venom reveals the worst part of the people and causes them to become evil. For example, Wendy turned against her sister Joanna, engaging in a fight.

Destruction
The Key was finally destroyed after a fight between Wendy and Joanna in "''Snake Eyes". ''The battle finally ended after Joanna stabbed Wendy in the hand with a barbeque fork, holding her arm in place, and cut the Snake from Wendy's hand using a pair of enchanted pliers. The Snake then disintegrated. The spell Joanna chanted to destroy the Serpens Clavem was "Dissolvere" ("Disappear").

Trivia
Serpens Clavem
 * The box which held the Key was actually seen in a previous episode. It was originally Freya's "Potion Box" in "Potentia Noctis".  However the prop was later modified for use in this episode.
 * In The Old Man And The Key the Serpens Clavem was cut off of King Nikolaus's arm when he was about to re-enter Asgard with Frederick.