Werewolf by Night

Werewolf by Night (birth name Jacob Russoff, legal name Jack Russell) is a fictional character, an anti-heroic werewolf in the Marvel Comics universe. The Werewolf by Night (usually referred to by other characters simply as the Werewolf) first appeared in Marvel Spotlight vol. 1 #2.
Werewolf by Night, Volume 1 ran for 43 issues during the 1970s. Issue #32 is notable for containing the first appearance of Moon Knight. Five 'Giant-Size' editions were also published during this time. Jack Russell also co-starred with Tigra in Giant Size Creatures #1, which was the first appearance of Greer Grant as Tigra instead of the Cat.
Jack Russell was dormant for most of the 1980s. The character's appearance was radically revamped in Moon Knight, Volume 1 #29. He guest-starred in various issues of Spider-Woman, Volume 1, West Coast Avengers, and Doctor Strange: Sorcerer Supreme.
Werewolf by Night was later revived in the pages of Marvel Comics Presents, where he appeared irregularly from 1991-1993. He also made regular appearances as a supporting cast member in the pages of Morbius, the Living Vampire from 1993-1995. A letters page in an issue of Morbius mentioned that a Werewolf by Night mini-series by Len Kaminski and James Fry was in the works, but the mini-series was never published.
Werewolf by Night, Volume 2 ran for 6 issues in the late 1990s. The series was written by Paul Jenkins and penciled by Leonardo Manco. After the book's cancellation, the story was continued in the pages of Strange Tales, which also featured the Man-Thing. That volume of Strange Tales was canceled after only two issues due to poor sales.
In early 2007, Marvel published a one-shot entitled Legion of Monsters: Werewolf by Night, with art by Greg Land.
Various Marvel comics throughout the month of May 2008 include a sneak peek of Moon Knight #20, which will feature Werewolf-By-Night. The three preview pages show Moon Knight fighting an enormous werewolf, while the written preview explains, "Something awful is happening out there in the back alleys that have become [Moon Knight's] new home. Blood-smeared walls raked with claws tell half the story. But to know the whole truth, Moon Knight will have to step into the arena and stare down a creature fueled by instinct and fury. To survive, he must become what he faces."