Jack Russel, born Jacob Russoff in Romania. His father, Gregor Russoff, was a werewolf and pass the curse to his son, Jacob.

Gregor was killed by a Angry mob when Jacob has only two years.

Later of this, Laura, mother of Jacob, took Jacob's sister and him to the United

States and marry Jacob's Brother,Philip.

The Family adopted the name of Russel and change the name of Jacob to Russel.

Unfortunately for Jack, he would go on to inherit his father's curse on his eighteenth birthday. Under the light of a full moon, Jack would transform into the Werewolf: a ferocious monster who would prowl the area searching for victims. He would hunt down and maim or kill evildoers as he encountered them, although he would often attack others when threatened or panicked. A number of these victims returned as werewolves themselves, only to be killed by Jack when he learned of his creations' bloodlust. Most of Jack's adventures revolved around him searching for a way to control or cure his lycanthropy. During this time he formed an on-again off-again relationship with the empathic sorceress Topaz. He eventually came to grips with his nature and is currently able to exercise a large degree of control over his actions while in werewolf form, to the point that he can usually think and act normally while transformed.

Soon Jack's werewolf form was scientifically enhanced by a Dr. Karl Malus whose treatment caused Jack to more closely resemble an actual wolf by having the head of a wolf and a small tail, this treatment also worked to augment his already high strength and agility..

Throughout the years Jack would encounter numerous heroes and villains, numbered among them Spider-Man, Moon Knight, Ghost Rider, Spider-Woman, Dracula, Avengers West Coast and the Midnight Sons. During a tustle with the Midnight Sons, the vampire hunter Blade was possessed by The Darkhold and killed Werewolf by Night; when the spell was reversed, Blade was returned to his normal state and Jack was revived via necromancy. More recently, Jack's niece was introduced as the Vampire by Night, whose hereditary curse had been modified by the bite of a vampire.

In the Legion of Monsters story arc, Jack heads to Salvage, Alabama to save the Pynchon family from an angry mob of townsfolk led by a religious extremist, Cal Escher. He finds Rhonda Pynchon alone, after her mother and twin sister choose death by their own hand over meeting the mob's wrath. Rhonda was found drinking away her sorrows at a local pub when the mob locates her and forces her transformation with the use of Tarot cards. At that point Russel bursts in and joins Rhonda in transformation, the two easily overpower the crowd and flee the city determined to use their affliction for good.

Powers

Werewolf by Night has the power of lycanthropy, the curse of the werewolf. As such his power is affected, but not entirely controlled by, the moon. The more full the moon in the night sky the more wolven Jack becomes. In his transformed state he has increased strength, dexterity and agility. He also holds heightened senses and a healing factor. Last, Jack has razor sharp claws and teeth as a wolfman.

His strength is not well charted, though he has been shown to easily out muscle such powerhouses as Sabretooth.

Jack can also choose to infect others with lycanthropy via a bite or scratch. For a long while, this was not a choice, all bitten by Jack would either die or become a werewolf. Though, after years of training and control, Jack can now choose who joins him as a creature of the darkness.

Alternate Realities

Earth-37072

This reality is ruled by Kulan Gath and Werewolf by Night is one of his servants.