Hybrid (Vampire+Werewolf)

Hybrids are a crossbreed between two or more different supernatural species. The term is commonly used to describe a Werewolf turned into a Vampire because they were the first type of hybrid to exist, however, they are not the only ones to exist.

A Werewolf-Vampire hybrid are potentially one of the most powerful pseudo-undead creatures, having strengths and characteristics of both vampires and werewolves. 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, like day-walking and being able to turn into a wolf form without the Full Moon's influence.

Creation
To become a vampire-werewolf hybrid, a werewolf must have either Klaus or Hope's blood in its system and be killed to begin transition. It is unknown lf normal vampire blood will Sire a triggered werewolf into a Hybrid but its unlikely. The transition will be successful only if the wolf completes his/her transition by drinking the doppelgänger's blood, Hope Mikaelson's blood works the same way as a doppelgänger's. So far, all non-original hybrids have been created by Klaus. Except for Hayley, who was created by Hope Mikaelson.

Presumably, a Werewolf does not have to have their lycanthropic gene activated in order to become a Hybrid, since Klaus became a Hybrid this way. After the first kill, the werewolf gene will trigger and the vampire will become a Hybrid, whether this is possible remains to be seen.

Without drinking the blood of the doppelgänger, the werewolf in transition will become unstable, bleed from the eyes, become rabid, and eventually die in pain from blood loss or some other internal reason, as shown on the pack Klaus initially turned. However, it is unclear why that happens. It might be a reaction to being fed the wrong blood in transition, but all unsuccessful hybrids were turned on a full moon night, meaning they possibly turned rabid due to the effects of the full moon.

It was initially believed that since the doppelgänger ( Elena) was resurrected, that the ritual wasn't fully complete, which is why hybrids must have died in transition; Bonnie confirmed this. Later, Klaus, assumed that the original witch would never help him. He gave  Tyler Lockwood, the blood of the doppelgänger - as a hunch, because it wouldn't have mattered as he would've died if he didn't complete the transition. Klaus had tried this method on a number of werewolves, but they all began to feel pain afterwards and started bleed through their eyes. They ended up dead, either from Klaus killing them, or dying themselves.

Klaus can still turn humans into vampires; by extension other hybrids likely can as well. Before it was revealed that Klaus' child can make Hybrids, every previous hybrid has been directly created by Klaus. Klaus revealed that the Original Witch who cursed Klaus had a fail safe - the doppelgänger had to die in the ritual to turn Klaus, but her blood was needed to turn any hybrids he tried to make. This was put in place due to avoid creation of new hybrids if Klaus were to ever break the curse. Klaus believes it was done as the Original Witch hated him.

It has been revealed that Klaus can have children thanks to his werewolf side, the child's mother is a full blooded werewolf, and her father is the original hybrid, so she's a werewolf-vampire-witch tribrid, half-werewolf, quarter-vampire and quarter-witch, as Niklaus was a Witch/Werewolf Hybrid during his first life.

It has also been revealed that the blood of Klaus' child can sire hybrids without the use of doppelgänger blood to complete the transition. It has been proven Tribrid blood is a powerful binding agent similar to doppelganger blood. This eliminates the need of doppelgänger blood during transition, though only the child's blood can finish the transition of a new hybrid, thus the Hybrid race still depends on a single and rare supernatural creature.

Powers and Abilities
Hybrids have the powers and abilities of both werewolves and non-original vampires/original vampires, both physically enhanced powers and abilities of mind compulsion. Non-Original Hybrids will grow stronger with age due to their vampirism and will also increase in strength when enraged, due to their Werewolf side. Their strength will also increase during a full moon. Klaus being a Hybrid that was an Original vampire, is physically one of the strongest beings around, his Hybrid condition allowing him to be slightly more powerful than his maternal half-siblings.
 * Super Strength - Non-original Hybrids are stronger than werewolves, non-original vampires and humans. Because of their vampire side, they also get stronger with age. The full moon will boost their strength and so will intense feelings of anger. Older vampires may be stronger and more challenging for many newborn hybrids. However, if a hybrid fights a vampire closer to their age range, the hybrid will win. Ray Sutton (a dying transitioning, unsuccessful hybrid) was shown to be very strong and nearly killed Damon until Stefan saved him, its likely the rabidness increased Ray's strength further to the rage rabidness causes. Hybrids are even capable of putting up a fight against Vampires well above their age range, however only when angered. This was seen when Tyler was able to momentarily gain the upper hand and bite Nadia. It should be noted that Nadia did manage to overpower Tyler eventually and escape, implying that she was still slightly superior in strength. Julian, while possessing Tyler's body, was able to fend off both Caroline and Stefan and even managed to kill the latter within an instant through heart extraction (which is ironic considering the number of hybrids Stefan and Damon have killed through the very same method). A hybrid in Werewolf-form will be immensely powerful and may be a slight challenge for even an Original Vampire as four normal Werewolves in wolf-form can take down an Original Vampire.
 * The "Original Hybrid" - Klaus is much stronger than immortals, non-original vampires, werewolves, non-original hybrids and humans. He is able to decapitate other species with a single chop and shatter windows and doors with small objects. He is even slightly superior to Original Vampires, even more so when enraged due to his werewolf heritage. The extent of his superiority over his maternal half-siblings is unknown, as Elijah has been able to fight Klaus on almost equal terms while Rebekah has been easily subdued, though unlike Elijah, Rebekah very rarely fights back. Klaus' strength is enough that he could kill twelve non-original Hybrids single-handedly, and was able to fight and kill twenty four non-original Vampires single-handedly with only some difficulty. As well as this, Klaus was able to temporarily fight Alaric when he had become an Enhanced Original, showing they had similar degrees of strength. Mikael was proven to be somewhat stronger than him in their confrontation inLive and Let Die.
 * Super Speed - A non-original Hybrid's intensified quickness, agility, reflexes, and endurance makes them faster than any werewolves, non-original vampires, and humans. Hybrids can use this ability in human or werewolf form. As with strength, Hybrids get faster with time. The full moon will increases their speed and being in Wolf-form will make them even faster. Tyler was particularly fast as a Hybrid, being fast enough to surprise Klaus and stake him.
 * The "Original Hybrid" - Klaus' intensified quickness, agility, reflexes, and endurance makes him much faster than immortals, non-original vampires, werewolves, non-original hybrids and humans, but only slightly more so than his Original Vampire siblings, as he once said, "I'm faster than your average vampire". He is able to stop other supernatural species in their tracks and run miles in mere minutes. His reflexes are similarly heightened, as he once caught Connor's arm before the latter could stab him with a small stake; he later saved both himself and Connor from an explosion intentionally triggered by Connor to kill both them and Damon.
 * Super Agility - Non-original Hybrids possess superhuman agility. They can move, jump, climb, and run incredibly fast without difficulty or exhaustion.
 * The "Original Hybrid" - Klaus possesses much more superhuman stamina, flexibility, reflexes, agility and dexterity than any immortals, non-original vampires, werewolves, non-original hybrids and humans but only slightly more so than Original vampires. He can move, jump very high, flip, climb and run incredibly fast without difficulty or exhaustion.
 * Super Human Senses - Non-original Hybrids have extremely keen senses of hearing, sight, touch, and smell that exceed those of non-original vampires, werewolves, and humans. Since their a supernatural crossbreed between Werewolves and Vampires, hybrids have the combined senses of both species thus making their ability extremely effective, Tyler Lockwood has been seen to use his super senses on multiple occasions such as when he overheard Katherine(in Elena's body) say that Caroline slept with Klaus or when he was able to hear Nadia compelling Matt but a prime example of this ability is in "Home" When Tyler is resurrected and hugs Caroline but then he tells her that it felt different, because he was no longer a hybrid.
 * The "Original Hybrid" - Klaus has a more enhanced sense of hearing, sight and smell that far exceeds those of any immortals, original vampires, non-original vampires, werewolves, non-original hybrids and humans.
 * Super Durability - Non-original Hybrids can bear a lot of trauma. They also hardly ever get tired or fatigued. Hybrids can take far more trauma than any non-original vampires, werewolves, and humans, without much discomfort or injury. Stakes and arrows does not seem to kill a non-original Hybrid when they are struck in the heart, they merely become unconscious, they are able to resist the bullets created by The Brotherhood better than non-original vampires as Stefan said to Tyler, that if he was a normal vampire he would be dead.
 * The "Original Hybrid" - Klaus can take far more trauma than any non-original vampires, werewolves, non-original hybrids and humans, without much discomfort or injury. However, like with his maternal half-siblings, he has never been dismembered throughout the series, implying that his durability may be close to invincibility though he can still be hurt. Wood, and White Oak Ash Daggers do not weaken him, making him virtually indestructible.
 * Enhanced Healing Factor - Non-original Hybrids have the combined healing capabilities of both non-original vampires and werewolves, rendering them practically invincible to anything but fatal wounds that can seriously impair their healing capabilities like decapitation or heart-extraction. They can recover/heal/regenerate from any injury much quicker and more effectively than any non-original vampires, werewolves and humans. They also seems to heal much more quickly when exposed to vervain, wolfsbane, or wood. Human blood has also known to make the healing process faster.
 * The "Original Hybrid" -  Klaus can recover/heal/regenerate from any injury much quicker and more effectively than any original vampires, non-original vampires, werewolves, non-original hybrids and humans. He also seems to heal much more quickly when exposed to vervain, wolfsbane, wood, or white oak ash daggers.
 * Mind Compulsion - A non-original Hybrid can compel the minds of humans. They cannot, however, compel original vampires, non-original vampires, supernatural hunters, Witches or Werewolves.
 * The "Original Hybrid" - Klaus can compel the minds of most sentient creatures; humans, non-original vampires and non-original hybrids. He cannot compel supernatural hunters that are members of the Five due to them being immune to mental manipulation. Klaus cannot compel werewolves, and Original vampires. His inability to compel werewolves was even confirmed by Ray Sutton. It is unknown if he can or cannot compel witches, but likely not, since not even the Original vampires are able to.
 * Immortality - Like non-original vampires, and original vampires, a non-original hybrid stops aging the moment they transition. They become immune to all conventional diseases, toxins, poisons, viruses, illness, infections, and injuries. As they are technically still werewolves albeit ones that are turned into vampires, they are likely immune to werewolf venom.
 * The "Original Hybrid" - Klaus is even more immortal than his descendants, Nothing short of immense magical power worth a hundred witches summoned by an exceptionally powerful witch and the White Oak Stake, can kill Klaus. Despite the extent of his immortality, Klaus still needs to feed otherwise he will desiccate and become immobile just like any other vampire, immortal or hybrid.
 * Dream Manipulation - Non-original Hybrids and Klaus can control dreams and subconscious like vampires/original vampires. They can produce and modify dreams, bestow nightmares or lucid dreaming. Other effects of this ability is the distortion of reality and trapped in the dreams.
 * Emotional Control - Due to their vampire heritage, non-original Hybrids and Klaus are able to exert certain control over their own emotions, e.g. They can turn off their humanity.
 * Enhanced Emotions - Because of their vampiric and Werewolf traits, non-original Hybrids and Klaus experience emotions more powerfully than humans and non-original Vampires. Particularly emotions such as anger, rage and aggression due to their werewolf heritage. Hybrids are more prone to violence and rage than non-original vampires. However, emotions such as love, joy, and happiness are intensified for them as well, allowing them to live life more intensely. This ability allows them to feel emotions at their peak regardless of their age. Klaus, The Original Hybrid, has been shown experience emotions as powerfully today as he did 1,000 years ago.
 * Shapeshifting/Transformation Control - Non-original Hybrids have the ability to transform into their werewolf forms at will. Most of them avoid transforming at all due to the pain it causes. They have complete awareness, but they still, however, have no control of their actions in werewolf form. They can also perform partial transformations, manifesting single features of their werewolf forms. Elijah informs Klaus that he remained a werewolf for two days, even when the sun was up. Showing that a non-original Hybrid can stay in Werewolf form longer than a normal Werewolf. As seen with Klaus when he bit Katherine, a non-original hybrid can transform partially, displaying their werewolf eyes and teeth.
 * The "Original Hybrid" - Klaus has the ability to transform into his werewolf form at will. Elijah informs Klaus that he remained a werewolf for two days, even when the sun was up. Showing that Klaus can stay in Werewolf form longer than a normal Werewolf. As seen with Klaus when he bit Katherine, Klaus can transform partially, displaying his werewolf eyes and teeth. It can be assumed that unlike non-original Hybrids, Klaus has complete control and awareness of his actions in his werewolf form.
 * Lycanthrope Enhancement - All non-original Hybrids and Klaus are capable of using their werewolf features to further supplement their powers and abilities. Both non-original Hybrids and Klaus can grow claws from their nails and werewolf fangs from their teeth even when they are still in their human forms. When Klaus was in Tyler's body, it was shown that a non-original hybrid's claws are sharp enough to penetrate a non-original hybrid's very durable skin. Also non-original hybrids and Klaus can display both sets of vampire and werewolf fangs. Their eyes also change into those of their werewolf form, presumably granting them better eyesight. Due to their werewolf heritage, a non-original hybrid and Klaus' strength and speed are heightened further during a full moon and at its peak in their werewolf form.
 * The "Original Hybrid" - Klaus is capable of using his werewolf features to further supplement his powers and abilities. Klaus can grow werewolf claws and fangs even when he is still in his human form. Klaus can display both sets of vampire and werewolf fangs. his eyes also change into those of his werewolf form, presumably granting him better eyesight. Due to his werewolf heritage, Klaus' strength and speed are heightened further during a full moon and at its peak in his werewolf form.
 * Werewolf Bite - Due to their werewolf heritage, non-original Hybrids and Klaus have venom which is fatal to non-original vampires and they themselves are immune to werewolf venom. Hybrid venom seem to take effect much faster than a werewolf venom.
 * Werewolf Bite Blood Cure - Klaus' blood is the only cure for a werewolf or hybrid bite, this ability seems to be unique only to Klaus as no other non-original Hybrid has been seen or mentioned using it, it can be assumed that Klaus' daughter Hope, can use this ability due to her being a pureblood hybrid.
 * Daytime Walking - Due to their werewolf heritage, non-original Hybrids and Klaus are immune to the lethal effects that u.v. rays and sunlight have on vampires. Allowing them to walk in daylight without the use of a day ring.
 * Procreation - Klaus can still have children with humans, werewolves, and witches, due to him being half-werewolf, so far Klaus is the only known hybrid to have this ability, it is unknown if non-original male Hybrids can have children with humans, werewolves, and witches, although it is very likely.
 * Immunity to Silver - Due to their werewolf heritage, magic bonded to silver doesn't affect non-original Hybrids and Klaus. Weapons made of silver might wound them, but the wound heals at super-normal rates than regular wounds.
 * Sire Bond - All non-original hybrids seem to be sired to the source of their creation. All hybrids turned by Klaus had a deep sense of gratitude and commitment to him causing them to obey his every command. When Hope Mikaelson's blood was used to turn a werewolf into a hybrid it obeyed Hayley's plea for help as she was still pregnant with Hope and in danger. It is later revealed that Hope's blood like Klaus's carries a powerful sire bond effect causing any hybrid created from her blood to protect and obey her. A hybrid is capable of breaking a sire bond, if it transforms into it's werewolf form an excess of 100 times in a row. Transforming so many times in a row causes them to no longer feel pain from transforming into a werewolf and they no longer feel a sense of gratitude, commitment or loyalty to their creator breaking the sire bond. Like non-original vampires/original vampires, hybrids can form a sire bond if the human they turn into a vampire has feelings for them before being turned. Although like non-original vampires/original vampires, this is extremely rare.
 * Telepathy - An advanced form of mind control that allows vampires to mentally communicate over a vast distance. Damon and Elijah have been shown to mentally communicate with others from a distance
 * Illusions - As seen with Lexi, vampires have the power to trick the minds of others into seeing/feeling things.
 * Immune: Hybrids are immune to angel blood

Weaknesess
 Invitation - Due to their vampire heritage, non-original hybrids and Klaus are unable to enter a home without an invitation.
 * Decapitation - The act of dismembering or removing the head of a non-original hybrid will result in an instant death.
 * Heart Extraction - Removing a hybrid's heart will result in an instant death.
 * Vervain - Non-original Hybrids are affected by vervain like their vampire counterparts. They can't compel anyone on vervain.
 * Wolfsbane - Non-original Hybrids are affected by wolfsbane like werewolves.
 * Magic - Witches are able to give supernatural aneurysms that cause the blood vessels of hybrids to explode.
 * The "Original Hybrid" - Magic can kill Klaus if a witch/warlock channels enough energy, however, considering his level of power. This would prove to be nearly impossible, any witch/warlock who attempts this, would dine the process before they succeed in killing Klaus.
 * Hybrid Bloodline - If Klaus or his daughter Hope dies, then all the hybrids they created will die along with them.
 * Wooden Stakes - Stakes can hurt non-original hybrids and neutralize them but it won't kill them.
 * The "Original Hybrid" - Stakes cannot neutralize Klaus, But he will still feel pain due to his werewolf side.
 * Hunter's Curse - If a hybrid kills a member of The Brotherhood of the Five, then they will be tormented by the hunter until they kill themselves or if the hunter is replaced then they will be free of torment.
 * Desiccation - Because of their vampire side, hybrids can desiccate without blood.
 * Broken Neck - Breaking a hybrid's neck will results in the Hybrid's unconsciousness.
 * Last Living Doppelgangers' Blood- If the doppelgangers' blood is used in the Magic Purification Spell, all of their vampire abilities will be stripped from them little by little and then they will be brought back to the last stage of their werewolf life: Death. They will then relive the way they died when they went into transition to the point where they die again.
 * The Devil's Star - The devil's star can cause a 1000 cuts onto another's body.
 * Animal Blood - As revealed in season 1, animal blood weakens a vampire's strength and presumably a hybrid's strength.
 * Physical Trauma - Minor physical injuries such as gunshots, stab wounds and broken bones will cause a hybrid pain and also slow them down. However, this is momentary as they will heal completely within seconds. It seems physical trauma can hurt them anywhere on the body (ex-eye gauging, drowning).
 * Power Suppression Necklace (possibly) - As seen in Every Mother's Son, Esther made a necklace to suppress Klaus' anger and powers as an untriggered werewolf, rendering him weak, but in control of his emotions. It is unknown if these types of jewelry would work on a triggered werewolf or a hybrid.