Jasper Cullen

Jasper is 6'11" tall and has honey-blond hair that falls to the middle of his neck. He is muscular, but thin, unlike his brother Emmett. Like the other Cullens, he has pale, marble-like skin, an inhuman beauty, and bruises like purple shadows under his eyes that appear gradually as his thirst increases. He has golden eyes like all vegetarian vampires, which become darker and eventually turn black as he becomes hungry. His original eye color was brown. He has many scars on his body, face, neck, and jaw from the bites of vampires he fought during his time in Maria's coven. These scars are invisible to humans unless contrasted with strong light, but when viewed by someone with supernatural vision, they are said to be his most dominant feature, causing defensive reactions in vampires who do not even know him. In Breaking Dawn, Bella believes the scars screamed "Danger!" She also asks herself, "How many vampires tried to kill Jasper?" and answers, "The same number that died trying."

Jasper can sometimes come across as cold, due to his military mindset from his time as a human in the Confederate Army and later as a vampire in Maria's army. However, the truth is that he is very kind, polite, gallant, and just a good person. Alice describes him as a "good Southern gentleman." He is a naturalist and an avid reader, as well as being astute in business and combat tactics.

He does not abuse his powers. Instead, he uses them to calm people around him or to help the Cullens be around people. Jasper also uses his ability to control people's feelings to calm down a situation and avoid fights (for example, in Eclipse, when the Cullens and the werewolves were hunting Victoria, he calms Emmett and Paul down).

In the Cullen family, Jasper is the best fighter, second fastest (after Edward) and second strongest (after Emmett). In Eclipse, during the training Jasper gives to the Cullens and the Quileutes, he noted that he could not defeat Edward due to his ability to read minds: neither could defeat the other (but without Edward's ability to read minds, Jasper would have defeated him). This was shown during their sparring match, which only stopped when Carlisle told them to, suggesting that it could have gone on indefinitely. In combat, he is a very brutal fighter and is difficult to defeat.

Carlisle Cullen is Jasper's adoptive father. Jasper first joined their family in 1950, two years after he met Alice.

While some vampires view Carlisle's lifestyle choices as inherently shameful (such as Caius), Jasper views him as humane and confident in living a normal life, even though he has trouble controlling his lust for humans.

Esme Cullen is Jasper's adoptive mother. Her passionate, loving personality brings comfort to Jasper, and Jasper loves her very much as a mother.

When he and Alice return from their secret camping trip in Breaking Dawn, Esme hugs them both tightly, accepting them back. This shows that Esme and Jasper are indeed very close to each other, as is the rest of their family.

Edward Cullen is Jasper's adoptive brother. He is very close to him, as is Emmett. Whenever the three of them are together, they enjoy fighting and often go hunting together. Since Jasper is the better fighter and Edward has telepathy to back him up, their fighting techniques are very well coordinated, as demonstrated in Eclipse when they prepare to fight Victoria's army.

Rosalie Hale is Jasper's adoptive sister, and uses her last name to ease the confusion they cause in people around them regarding their relationship with Alice and Emmett Cullen.

Due to their similar appearance, Jasper and Rosalie are portrayed as twins during their time at Forks High School, and are adopted by Carlisle and Esme Cullen. The details of their relationship are unknown, but it has been suggested that he cares for her as a sister.

Bella Swan is Jasper's adopted sister-in-law and Edward's wife. Jasper was initially worried about their family secret when Edward saved her and then revealed his vampire nature, and planned to kill her. He was stopped by Edward and Alice, who convinced him. After Bella and Edward began dating, Jasper warms up to their relationship, although he often has trouble controlling his thirst.

Renesmee Cullen is Jasper's adopted niece, and the biological daughter of Edward and Bella. Jasper was concerned for Bella's safety when she was pregnant with Renesmee, but it didn't help when Rosalie, Esme, and Emmett sided with her while Edward and Carlisle wanted an abortion. He simply acted as the family's guard when Sam's pack planned to attack them.

After Renesmee was born and Bella became a vampire, Jasper was always there to keep Bella from attacking her daughter. One day, he misinterprets Edward's sudden alarm and immediately immobilizes Bella, handing him the baby.

It is unknown how close Jasper is to his niece after she was born, as they never spent any time together. But since they are members of the same family, it is implied that they care for each other.

Jacob Black is the alpha male of the Black Pack. Jasper and Jacob's relationship started out casual due to their status as natural enemies, becoming slightly friendlier when both sides formed an alliance to destroy Victoria's army, and the wolves became willing to train under Jasper to learn the strengths and weaknesses of newborns. This loyalty allowed both sides to tolerate each other's existence after the battle. Jacob finds Jasper's fighting skills very intense and useful. When the Hive Pack plans to kill Bella to prevent her from being born, Jacob breaks away from the pack and allies himself with the Cullens again, along with Leah and Seth.

Jacob becomes more involved with the Cullens after imprinting on Jasper's niece, Renesmee, and subsequently becomes closer to Jasper.