In the 5th edition Dungeons and Dragons Monster Manual, on page 206, you will find a section on Lycanthropes: Werebears, Wereboars, Wererats, Weretigers and Werewolves. It has a section on being infected with the curse, a saving throw to prevent becoming a lycanthrope and stat blocks for each type of were beast. But it lacks a certain something, being a lycanthrope is overly beneficial. So this is my variation to make lycanthropes more interesting for role playing.
First and foremost, Lycanthropy is a horrible curse that removes a persons agency, and can force them to roam the world in a beast form and behave in a ferociously evil manner, on nights of a full moon. When bitten, or wounded by a lycanthrope’s claws, a person undergoes a trial as the curse tries to take hold over subsequent lunar cycles.
The curse goes through three stages: Unwitting, Aware and Complete.
During the Unwitting and Aware phases the cursed character may throw the curse off by sheer fortitude but once they have become a complete lycanthrope only the magical powers of a remove curse or wish spell will cure them.