Hybrid

Hybrids are a cross-breed of two or more different supernatural species. The term is commonly used to describe a witch turned into a vampire due to the fact that they were the first supernatural hybrid to be introduced by Jace Wynn. However, since the witch-vampire hybrid's creation, there have been other cross-breed hybrids revealed, such as werewolves turned werewolf-vampire hybrids, and in the rare case of Phoenix Walter, a phoenix-hellhound hybrid.

Hybrids possess both the strengths and some of the weaknesses of their parent races, along with powerful attributes unique to themselves alone due to their combined heritage. For werewolf-vampire hybrids, this includes Day Walking and being able to transform into a wolf without the Full Moon's influence. For maven-vampire hybrids, they retain their ability to draw magic and their own vampirism as a power source for their use in witchcraft; as they did not possess their own magic as humans, this is a skill that makes them powerful.

Amara's Doppelgängers
Amara's doppelgängers are Tatia, Katherine and Elena, all three of which have appeared on-screen. Elena is sometimes referred to as the Petrova doppelgänger because of her striking resemblance to Katerina Petrova.

With Amara's death and Elena being the last doppelgänger, the Petrova doppelgänger line is expected to be extinct with Elena's death.

Tatia Tatia was born during the 10th century A.D. in the area where Mystic Falls was to be formed. She was a contemporary of the Mikaelson Family around the early 10th century. During the Middle Ages, Tatia had a child with an unknown man; later in time, she met Elijah and Niklaus Mikaelson, both of whom fell in love with her (especially Klaus, according to Elijah). Esther, the mother of Elijah and Niklaus and also the Original witch, used Tatia's blood in the spell or ritual to create the Original Vampires, as part of the wine laced with blood in which Mikael had given his children. Her blood was also part of the spell Esther used to bind Klaus' werewolf side, which resulted in Klaus' werewolf gene being dormant.
 * -|Tatia=

Katerina Petrova Katerina Petrova (a.k.a. Katherine Pierce) was born in Bulgaria during the 15th century on June 5, 1473. In the year 1492, when she was still a human, she was captured by Klaus. She knew that she was going to die, so she tricked Trevor, one of Klaus' servants, into helping her escape. Katherine was clever, cunning and smart; she knew that if she became a vampire, she'd be rendered useless to Klaus. Katherine stabbed herself with a knife but was given vampire blood by Rose in an attempt to heal her stabbing wound and afterwards, Katherine hung herself and came back as a vampire. In return for her escape, Klaus made her suffer by killing her entire family in Bulgaria, thinking that the doppelgänger would never appear again. What Klaus didn't know was that Katherine had a child out of wedlock that was kept secret and this child continued the bloodline of the Petrova family, leading to the birth of Elena Gilbert. Tired from running, Katherine intended to make a deal with Klaus by giving him the ingredients he needed to break the curse in exchange for her freedom. She planned to hand over the moonstone, Elena Gilbert, Caroline Forbes (a vampire), Tyler Lockwood (a werewolf) and Bonnie Bennett (a witch). When Katherine was about to take out her own doppelgänger, Elena shoves the cure, into her mouth. She is the doppelgänger of Tatia and her doppelgänger is Elena Gilbert.
 * -|Katerina=

Elena Gilbert Elena Gilbert was born in Mystic Falls, Virginia during the 20th century on June 22, 1992. Elijah was the first one who found out about Elena before Klaus. At first, when Rose told Elijah about this, he didn't believe it. But soon enough he found out that the Petrova Family line didn't end with Katherine because she had given birth to a baby girl, thus continuing the Petrova bloodline. Once Klaus learned of the Petrova doppelgänger, Elena, he came to Mystic Falls, and he kidnapped Katherine, temporarily taking over the body of Alaric Saltzman. As with Katherine, Klaus is responsible for the death of Elena's family, most notably their aunt Jenna Sommers, Elena and Jeremy's legal guardian. He terned Jenna into a vampire and killed her for the sacrificial ritual. Unlike with Katherine, Klaus successfully killed Elena and as a result, he breaks the curse. Fortunately for Elena, John Gilbert had Bonnie form a special spell that bound Elena's life force or essence to his. This spell brought Elena back to life, but in return, killed John and took his life. In The Departed, Jeremy took Elena to Mystic Falls Hospital after discovering her lying unconscious at home. Meredith Fell discovered Elena was suffering from a serious cerebral hemorrhage and secretly injected her with vampire blood to heal her. This action fortunately saved Elena from death. The same day, Rebekah ran Elena and Matt off Wickery Bridge to save her siblings from Alaric, since his life force was tied to Elena. That way, if she died, so would Alaric. Jeremy arrives home to see Alaric, and he talks to him and Jeremy realizes that he is a ghost, and that if he is dead, that means his sister, Elena, must also be dead. Stefan hurried to Wickery Bridge, intending to save Elena, but she insisted that he save Matt's life instead, who was unresponsive after crashing into the water. By the time Stefan pulled Matt out of the water, Elena had drowned and died. Stefan brought her body back to Mystic Falls Hospital, where she woke up, transitioning into a vampire with Damon's blood in her system. She is the last of Amara's doppelgängers. She later reverted back to human after taking The Cure.
 * -|Elena=

Known Hybrids

 * Original Vampire-Werewolf Hybrid - Niklaus Mikaelson
 * Werewolf-Vampire Hybrid - Hayley Marshall  (formerly), many deceased hybrids, Tyler Lockwood  (formerly)
 * Witch-Vampire Hybrid - Valerie Tulle, Malcolm, Mary Louise, Nora Hildegard, Beau, Oscar, Malachai Parker
 * Witch-Werewolf Hybrid - Niklaus Mikaelson  (formerly) , Vivianne Lescheres  (books)
 * Witch-Werewolf-Vampire Tribrid - Hope Mikaelson