Werewolf is from the supernatural monster side of Marvel with MoonNight, Blade, Morbius etc. Sometimes he's bad because he can't controll the changes and sometimes an anti hero when he can controll it. He was a part of the Midnight Son's anti hero team for awhile.
Werewolf by Night who's name is Jack Russell, is a supernatural character that debuted in 1972 and his arch nemesis is Moon Knight. Also this is a TV special (short film) not a series, so it's a one-off.
There is a Dracula, Were Wolf and Frankenstein’s Monster, N’Kantu the Mummy, Hit Monkey (a monkey that channels an assassin), Man Thing , The Creature from the Black Lagoon and a Zombie and they all work for Shield as the Howling Commandoes. This movie is before Fury puts them all into a team. The only two I see in the clip are the Were Wolf and Man Thing but I hope this leads to a Commandoes tv show
TVA Agents from Loki are in this. Also Elsa Bloodstone who will appear in the Blade movie and Man-Thing is there as well as Werewolf by Night off course.
You guessed it buddy, werewolf by night is a character based on Marvel comics. *A HORROR COMIC!* According to what I dug up, the Werewolf by Night is the name applied to two fictional characters who are werewolves appearing in American comic books published by Marvel Comics. The Werewolf by Night first appeared in Marvel Spotlight #2.