|“||My family has no shortage of enemies, and she will inherit all of them.||”|
|“||Every king needs an heir.||”|
— Niklaus changes his opinion about the baby.
In the episode The Originals, the witch Sophie revealed that the werewolf Hayley was in fact pregnant with Klaus' child. She revealed that the baby is one of natures so called "loopholes". She later revealed that it was because of Klaus' werewolf side that it was conceived. Sophie then demands that Klaus help her or she will kill the baby and it's mother.
Niklaus initially had no interest with having anything to do with the child, even telling to the witches that they made a mistake if they thought they could get to him by using Hayley and their child as leverage. But after words of consideration from Elijah, and an exchange from Camille (the brave bartender), he later changes his mind. When Elijah asked him about Hayley and their unborn child, Klaus replied to him that "every king needs an heir".
In Always and Forever, Elijah tells Sophie that he believes this child will be a way for Klaus to finally be happy. Sophie is glad he feels that way, as she blackmails him. If he gets Klaus to co-operate with their demands, since Marcel already drove the werewolves from the French Quarter, nobody will have to know of the existence of a hybrid baby. In a later phone conversation with Rebekah, Elijah swears he will not let anything happen to the baby.
In House of the Rising Son, When Rebekah arrives in New Orleans looking for Elijah, she meets Hayley, commenting her "supernatural, miracle baby bump" isn't showing. After a short conversation with Niklaus about the whereabouts of their elder brother, Rebekah takes Hayley to the basement of their house, showing her the coffins, before warning her to get out of New Orleans while she can, because once the baby is born, Niklaus will be "planning a coffin for her." Hayley comments that the witches cast a spell; if she leaves New Orleans, she and the baby will die.
Rebekah's words clearly affecting her, Hayley heads to Jardin Gris, inquiring wolfsbane in an attempt to abort the baby. She sits on a bench at night, pouring the poison into a cup of tea, urging herself to drink it. She is about to drink when she hears rustling behind her. Vampires appear in front of her, saying wolves aren't welcome. Hayley, fed up of being told what to do by vampires, tosses the cup at him and attempts to flee. Rebekah suddenly shows up, ripping the heart out of one of the vampire's, and snapping the neck of the other, saving Hayley's life. After Klaus hears of Hayley leaving the house, he berates her and demands to know what she was doing. In a rage, Hayley growls that she wanted to put the baby out of it's misery, a comment which Klaus begins to choke her over, showing he clearly cares for the baby.
The day after, Klaus slowly walks into Hayley's room whilst she is supposedly sleeping. He notices the bottle of wolfsbane and sniffs the top. Hayley then tells him that she didn't use it, Klaus asks her why, as she could've been free from "all of this." Hayley says that when she was being attacked, she wasn't just protecting herself, she was protecting her child and she didn't want to let anyone hurt it.
In Tangled Up In Blue, Hayley is walking by the pool at night, and she suddenly looks up to see herself face to face with a wolf. Sabine suddenly appears and tells her that the wolf is drawn to her because of the baby, before telling her that she knows some charms in which can reveal the baby's gender, admitting that it is not really magic that she will be using. Later on, Hayley is lying on a kitchen table with Sabine dangling a pendant over her stomach. She tells her that she thinks it's a girl before suddenly stopping. Hayley says "don't tell me I'm having a mini-Klaus" before Sabine drops the pendant and gasps, repeating the same sentence leaving Hayley confused at her words. Some time later, Klaus walks into the room whilst Hayley is seated on her laptop, and she reveals that she thinks their child is a girl; unseen to her, Klaus smiles at the news. As he leaves, Hayley is seen typing the sentence Sabine repeated onto her laptop.
In Girl in New Orleans, Agnes persuades Hayley go to a doctor out in the bayou. The doctor tells Hayley that her child is healthy. Then Hayley is attacked by some witches who attempt to kill her and her baby, but she manages to escape and fight them off, until Rebekah eventually comes to save her. However, they are both then shot, and Hayley goes missing. When Hayley shows up later, she has forgotten what has happened, but believes that a wolf is looking after her, and has killed the witches after her to protect her. Her wounds have also all healed, and is revealed that her own baby has healed her due to it's vampire healing blood, inherited from it's father, Klaus.
In Fruit of the Poisoned Tree, Agnes enacts a plan to kill the child, by using the link between Sophie and Hayley. She uses a cursed object to cause Hayley's temperature to spike rapidly in order to cause a miscarriage. Sophie works with Elijah to lower Hayley's temperature and heart rate, until Davina, through Elijah's machinations, could unwittingly severe the link between Sophie and Hayley, saving the baby's life.
In Bloodletting, it is revealed that the baby's blood is capable of turning werewolves into hybrids. However, the hybrids created are sired to its mother - likely due to it and her being one and the same for the time being. Tyler Lockwood kidnaps Hayley, and tries to kill the baby, as he believes that Klaus desires to use the baby to sire a second army of hybrids. Klaus scares him off, however Tyler then goes to Marcel, and informs him of the baby's existence, and that its abilities will prove a threat to the vampire kingdom.
In The River in Reverse, Klaus mentions how he believes that his child will grow up calling Elijah father because of the way Hayley adores him and how his siblings don't believe that his intentions toward his own child are pure. He later states that his child is all that matters to him now.
In Reigning Pain in New Orleans, Klaus tells Marcel how the witches forced him to help them take down Marcel by threatening to kill his unborn child. He goes on to mention how at the beginning he didn't care for his own child, but after remembering how Mikael despised him since birth he had a change of heart because he doesn't want to end up being exactly like his father was to him. Elijah also reveals that descendants of Klaus' father are still alive (Cary is a descendant), therefore meaning relatives of the child as well.
In Après Moi, Le Déluge, the baby becomes part in the plan to complete the Harvest, and also to prevent Davina's power from destroying all of New Orleans. Using the fact that the baby is alive, and therefore able to own property, the Original vampires bury and consecrate their mother's remains with Kieran's help and Esther becomes a New Orleans witch. As her children, The Originals act as a conduit of her magic, so the Sophie can channel the power.
In Dance Back from the Grave, Elijah bites Hayley so he can use the power of the baby's blood since the baby is a quarter witch to free Rebekah from a spell cast by Papa Tunde.
In Farewell to Storyville, Rebekah says to Hayley that the Mikaelson family has enemies, and that when she is born she will inherit all of them. She also says that, though Niklaus is a dangerous person, there is hope for him, and the baby is a focal point of that. Finally, she asks that Hayley tell the baby stories of 'her crazy aunt Bex' and, despite her absence, she really does love her niece.
In Moon Over Bourbon Street, Klaus tells Jackson he counts on the werewolves sense of unity to protect his unborn daughter. Elijah and Hayley also express their concern for safety of the baby. Elijah suggests to Hayley to come back and live with him and Klaus. Hayley however declines his offer.
In The Big Uneasy, Klaus tells Elijah that, while he feels Hayley and the baby will be better protected in the bayou with the Crescent wolves, he will bring Hayley back before she goes into labor. Klaus wishes the baby to born in the compound. The child later kicks for the first time onscreen when the wolves are telling campfire stories, and Hayley puts Jackson's hand on her belly so he can feel. Monique later tells Genevieve that the baby must die in exchange for Genevieve's life.
- Sophie describes the baby as "one of nature's loopholes" in The Originals.
- Elijah believes Klaus' child is the key in reuniting his family.
- Elijah has sworn to protect the child no matter what.
- The child was able to heal Hayley from her injuries sustained in Girl in New Orleans.
- Sabine did a test to see whether or not the baby was a boy or a girl, and while it did say girl, she openly admitted that their was no magic behind the test.
- Sabine also had a vision that the child will be the death of all witches. This could possibly be false as it was used to precipitate the death of the last living elder Agnes.
- In Bloodletting, it was shown that the baby's hybrid blood can turn other werewolves into hybrids, causing them to be sired to Hayley. However, once the baby is born, it is likely that the sire bond will shift to her.
- The vampires now believe that the baby will be their end, due to Tyler Lockwood informing them that the she will be able to make an army of hybrids that will wipe out the vampiric race, due to hybrids being able to walk in daylight, without the use of a day-walking ring, and kill vampires with a single bite.
- Klaus believes that if Elijah and Hayley engage in a relationship, the child will grow up to call Elijah father instead of him.
- Klaus mentioned in Reigning Pain in New Orleans that his child is the only thing that matters to him.
- According to Eve, many werewolves have heard about Klaus and Hayley's unborn child, and have come to New Orleans to see this miracle pregnancy for themselves.
- Descendants of Klaus' father were revealed to be alive, meaning Klaus has relatives from his paternal side of the family, therefore the child does as well.
- As mentioned in Après Moi, Le Déluge, the descendants of Esther would be allotted her power due to the consecration of her remains. Thus it is possible that the child will be able to channel the power of Esther.
- As the only living descendant of Esther, this child is capable of owning property, something which vampires (including even Original vampires) themselves can't do. This was confirmed in Après Moi, Le Déluge; where this fact was used to consecrate Esther's remains at the plantation (the deed to which is held by Hayley), thus enabling the Harvest Ritual to be completed by Sophie (who channeled Esther's power to become a witch elder).
- Hayley confirmed in Dance Back from the Grave, that the baby is a quarter witch. The baby has the blood of three species in her; vampire, witch, and werewolf.
- In keeping with the Mikaelson Family's status, the baby is an "Original" - the first of a new race of hybrids.
- The child has a connection to three supernatural groups New Orleans Coven, Crescent Wolf Clan and Original Vampires.
- The child appears to be breaking a universal rule regarding magic; that a being can only be a vampire or a witch, but never both, which may be the bigger reason why Nature has sent the witches to kill her/him.
- The reason Klaus was able to procreate sexually where other undead beings cannot is that he is not a vampire, but a hybrid. It is unknown whether his gene being triggered after he was turned has anything to do with it.
- As the first living vampire/hybrid, regular vampire traits may not apply to this child.
- The baby is also the first natural vampire/hybrid.
- The mixture of the baby's blood makes her one of the most powerful beings in The Vampire Diaries and The Originals, given the fact that it has the combined powers and abilities of vampires, werewolves and witches.
- In The Big Uneasy Klaus states that his pack, and thus his child's pack, is from the North East Atlantic.