Denali coven

The Denali Coven is a vampire coven (though they prefer the term "family") comprising of Kate, Garrett, Carmen, Eleazar and Tanya. The Denalis are among the few vegetarian vampires in the world, along with the Cullens. They are very close to the Cullens, being some of the Cullens' most loyal allies and considering themselves their extended family. The Denali Coven is located in Denali, Alaska so that its members can live alongside humans without too much trouble.

History
Originally, the coven consisted of Sasha and her "daughters", Tanya, Kate and Irina. At an unknown time, Sasha also secretly created an immortal child, Vasilii. When the Volturi found out, they came to destroy the entire group, but only killed Vasilii and Sasha, since the others knew nothing about him.

The sisters are the originals of "succubus", a creature in the form of a beautiful woman who has sexual intercourses with men before killing them. Tanya, Kate, and Irina often entertained themselves by romancing local human men, but soon, the men would become the meal; their relationships with human men never lasted very long. Eventually, they grew lonely over the years by the scarred pain of their deceased mother and some of the men they'd killed. Tanya decided to try a vegetarian diet to see if she could gain control to avoid killing men while sleeping with them. The method proved correct, and Kate and Irina joined her. The sisters then relocated to Denali for its wide population of animals, and they learned to avoid killing men during sexual intercourse.

At some point, the vampires Carmen and Eleazar found the three sisters and joined them. Also at an unknown time, they met the Cullen family, and the two covens became strong allies and close friends, though they preferred to think of each other as cousins due to their similar diet. Tanya developed romantic feelings for Edward Cullen, but he did not reciprocate.

New Moon - Eclipse
A vampire named Laurent eventually comes to stay with the Denalis after recently leaving a coven of non-vegetarian vampires, and is ready for a change in his life, which happens when he and Irina fall in love. At one point, however, he returns to Forks as a favor to his old friend, Victoria, to 'get the lay of the land for her' so that she can hunt Bella Swan. While he is there, he runs into Bella in the middle of hunting. When he is about to kill her personally, a pack of shape-shifters, who the Cullens happened to have a treaty with, kill him before he could get to her. A little under a year later, the Cullens call for aid from the Denalis after finding out that Victoria is creating an army of newborns to destroy the Cullens and kill Bella. The Denalis agree to help them, but at Irina's request to avenge Laurent's death by wiping out the shape-shifter pack. Carlisle refuses to allow this, and the Denalis abandon their long-time friends. The Cullens are forced to form an alliance with the shape-shifters instead, and successfully kill Victoria and destroy her army.

Breaking Dawn
The Denalis later feel terrible about abandoning the Cullens. Soon after the battle, the Denalis, except Irina, attend Bella and Edward's wedding. A few months later, Irina decides to visit the Cullens and finally make peace with them about Laurent's death. When she arrives in Forks, however, she sees Bella hunting with her shape-shifter friend, Jacob Black, and what appears to be an immortal child (Renesmee). Remembering Sasha's fate and her anger at the Cullens for not avenging Laurent's death, she goes to the Volturi and reports the Cullens' "crime". The rest of the Denalis are once again called upon by the Cullens for aid. Renesmee, the child Irina had seen, is really Bella and Edward's half-human half-vampire daughter. The Denalis, after some persuasion, agree to testify this for the Cullens against the Volturi. Kate and Tanya also help Bella practice her power and fighting skills to prepare her for a potential battle.

When the Volturi arrive, Irina realizes she had been wrong. After admitting this, Caius has her killed to try to provoke a fight. His efforts failed, and the Volturi depart after Aro decided Renesmee is not a threat. The remaining Denalis return home after the confrontation. They are joined by the nomad Garrett, who is said to have joined the Denalis due to his romantic feelings for Kate.

Members

 * Tanya
 * Kate - Electric current
 * Carmen
 * Eleazar - Ability identification
 * Garrett

Former members

 * Irina (killed by the Volturi for providing a mistaken testimony against Renesmee Cullen)
 * Laurent (killed by the Quileute werewolves/shape shifters)
 * Vasilii (killed by the Volturi for being an immortal child)
 * Sasha (killed by the Volturi for creating Vasilii)

Denali Coven extension
On the basis of their similar diet, the Olympic Coven is considered a loyal extension of the Denali coven, calling themselves cousins. In Breaking Dawn, Tanya apologizes for not aiding the Cullens in the newborn army crisis and states that she and her coven mates are part of the Olympic Coven, too. The Olympic Coven consists of Carlisle, Esme, Edward, Alice, Emmett, Bella and Renesmee Cullen, as well as Rosalie and Jasper Hale.

Succubus legend
The Denali coven's female vampire used to lure men to their death by seducing and engaging in sex with them, before feeding on their victim. However, on the long term, the strain wore on them and the Denalis started to feed on animal blood. They, however, kept enjoying the company and nocturnal activities with men, both vampire and human, which by now could survive the experience. This may also be the origin of the succubus myth: a demon that assumes a woman's aspect seducing men to have sex with it.

Trivia
The Denali coven is the third largest vampire coven in the Twilight Saga, comprising five vampires. Including the deceased members, the tally goes up to nine members.